Overcharging

I have been a Vodafone customer for 13 years. I trusted Vodafone as everything was great for tye first few years.then last year I noticed my bill almost doubled.I phoned Vodafone and they knew it was not right and sorted it. I then started to look back all my bill. To my shock for about 5 years they had been charging me for things I used or had. I contacted them and was basically shouted at by customer services, I was trying to explain where and when it all started but he would not listen. For months I was neve off the phone as I would ask for copies of my bills that I did not have, was give the run around for almost 5 months. I then said I would pay no more and and was going to ombudsman to get it resolved. I was not owe them money but they cut my phone off and told me I would get it back on when they had requested paperwork that they had to get back within theor own company. A man named omar in customer resolutions team blatantly lied to me on the phone and he and his senior left me on hold for almost an hour for no reason. All this resulted in bank charges even affecting my credit scoreand was paying for a phone contract that they turned off.luckily I had all the evidence to prove that they had been over charging me. They then offered me me £357. Off my bill but I was never even owe that money in the first place so all they were doing was correcting their mistakes. I spent 7 months having to get it sorted some days I would have to call 5 or 6 times as they would say yes sort it now then wasn't. For all the hassle and stress of being lied to almost every day for 7 months having no phone and credit score affected. They offered me nothing. They said as a good will gesture they would wipe the bill that I never owed them. That was only for last year. I will now be going back to ombudsman with all my evidence of bills bank statements of when it started 5 as I never got the past bills resolved. Feel totally let down by a company I had been with 13 years and was treated in a discussing manner through it all. Can definitely say I won't be renewing my contact and wI'll be not recommending them to friends and family