Appaling billing; take too much on direct debit; do not use

My account accumulated a large amount of credit over 2015 and I spent many a lunch hour in their telephone queues trying to get the issue resolved, which appeared to be hampered by their IT systems refusal to enter gas readings; gas readings which I read directly from the meter and tried to submit many many times both by your web site and by ringing them (although this would nearly always fail due to my lunch hour only being one hour long – incredibly frustrating I have far far better things to do in my lunch hour as you can imagine).
Due to not being able to get the issue resolved, I eventually, under the guidance
of a friend who is an accountant, stopped the direct debit which was obviously taking too much money every month.
The stopping of the direct debit resulted in me being charged extra daily tariffs. This felt like being penalised for failings in COOP ENERGYS systems. Again, to try to resolve this new unfair twist, I kept ringing and being put in various telephone queues, sometimes only, after a 20 minute wait, being diverted to
messaging services (which never seemed to pass messages on). Finally, after many many attempts, I got through to a real customer service coop account supervisor and told him the meter readings; he then produced a bill and I was told
this resolved to around 500 pounds had accumulated as credit. Amazingly, he asked if I would like the COOP to keep some of it! I requested it all sent back. I was promised a cheque (even though I requested a bank transfer; I did not think cheques were still in use) which was apparently ordered on 22OCT2015 (i.e. days later than I had requested it and after more phone calls to chase it being issued).
This `cheque' took over two weeks to arrive.
Because the cheque did not arrive within the two weeks promised, I phoned the energy ombudsman and they told me to raise a formal complaint and gave me a reference number; they told me that I would be given a reference number by coop on raising the `formal complaint'. COOP seemed unable to give me a formal complaint number. I assume that in failing to do this COOP have broken the law and/or regulatory guidelines. I phoned, finally reaching an operator who gave me a name in the Walsall office at coop energy, and stated that I wanted to raise a formal complaint. Whilst I repeatedly requested a formal complaint number she seemed
unable to supply one. While I remained calm and polite I did feel that this was deliberate obstructive behaviour. I speculated that this could have been psychological tactic to make people angry so that the operator could have cause to put the phone down on the customer. I kept calm and kept asking for a formal complaint number or to be passed to someone who could supply one.
Eventually, she said that I would be phoned back within 72 hours and given a coop energy reference number by a different department. I found this very strange and was worried that it may have been some stalling tactic to reduce the actual number of formal complaints raised (i.e. fobbing off). I re-rang the ombudsman, who told me that as I had the name of the coop account assistant the date could be used as the start of the eight week count down until they could become involved. The ombudsman logged this info against the reference number they gave me. For the record, no phone call, as promised, was actually returned within 72 hours. So this `call-back promise' turned out to be untrue and could easily be interpreted as a fobbing-off/lying tactic.
As soon as I had received the cheque, far past the promised two weeks from when
it had been belatedly ordered; when it had actually cleared, I changed supplier. Incidentally, I have had no problems with this new supplier and find their web site simple to use for entering meter readings. My reasoning for not leaving COOP energy in say the summer was that if I simply left it may have been extremely difficult to get the credit that had been erroneously accumulated. Once I was refunded the money I changed supplier immediately. I initially changed supplier because I was under the impression that the COOP was a more ethical organisation to buy energy from. Now I am utterly disillusioned by your appalling service and am tempted to actively avoid any COOP branded service; in fact I now have negative feelings towards
the COOP organisation in general. I feel betrayed. I tried to “do the right thing” and got royally mucked about. COOP you should be ashamed of yourselves.

Its been about four months since I left and they STILL have not issued a final bill. They send me threats of debt agencies and meaningless bills with daily tariffs accumulating but no energy usage.

Moral of the story don't use COOP energy, and if you start to have trouble, start the ombudsman process as soon as possible. There is an 8 week delay built into that process, so start it at the first hint of trouble.