Basically DO NOT USE O2. You have been warned. I have been a loyal customer for years and last year around October (2015) they developed an online payment issue. Google it to see how bad things were. No matter what we did we couldn't pay our bills. This went on for months. Hundreds of email, texts, replies on twitter and phone calls and nothing was resolved. I was off work recovering from cancer so had extra time to try and solve it. But nothing helped. O2 refused to acknowledge the issues and blamed the customer and lied every single time i contacted them. Out of desperation i told them to end my contracts. I did not want to do this but all of my devices were blocked despite my efforts to pay. Then they tried to charge me £80 per device extra for early cancellation. I refused. I know this is their policy for customers who want to cancel but they forced me to do this. After months of getting nowhere with them they put all this as defaults on my credit record and really affected my life. I have had to pay everything in the end to try to get this solved and get them out of my life. But we aren't finished yet. I received a letter this week telling me they've reconnected one of my devices and i owe them yet more money!!! I hate this company. They are ignorant, rude, useless and disgusting. They have ruined my otherwise good credit record, caused problems with my family and delayed my recovery. This is an extreme case of appalling customer service but beware as this awful company can do this to anyone. I can't afford a solicitor or i'd take them to court. All i can do is let as many people know about what they do as possible. Please please think twice before getting a contract with the worst mobile service provider ever. You will be sorry.

I have complained many times about on line payment system and yet today it is still not working can O2 please get there acts together and fix this problem

Be aware that it seems although you sign a contract for 24th months and choose your phone and a tariff based on what you can afford. O2 can & will increase there tariff costs, using the cost of inflation as an excuse. Here is a snippet from the email they sent me, it was the same last year as well. "with the current Retail Price Index (RPI) rate of inflation at 2.7%, the cost of everything is going up. As a result, we're adjusting the price of your tariff in line with RPI. This means when you get your March 2014 bill, it will be updated from £xx to £xx. Apparently they are doing it to, I quote "At O2, we want you to have the best digital experience possible. That's why we're always investing in the best technology" Am I the only one who ends up paying extra again when I subscribe to these so called new O2 mobile services" But apparently all is not lost, according to O2 "Exciting times ahead" They look forward to bringing us more great value for money services and all the latest technology, including: O2 Gurus - Haven't we already got this? Priority Moments - Hmm yes this is also an existing service of which ive never found to be that great. Priority Tickets - Another existing feature. O2 Wifi - hotspots. Another existing feature. 4G - Well correct me if I'm wrong but when it does finally cover a higher percentage of the UK, wont we be charged extra for this as well ? The O2 head of consumer marketing finishes off his email to me by reassuring me that "we won't stop there. We're going to keep on bringing you even more value and exciting technology. Just watch this space." Well I would like to thank their Head of Consumer Marketing for ensuring that we pay more for what we have already got. Maybe all mobile companies are the same but be aware even if you think your picking a fixed tariff with O2, your not.