I signed up to O2 50GB tariff in September 2018 and decided to pay for the device up front to make the monthly payments cheaper (£22 per month instead of £29). Everything seemed fine for around four months until out of the blue I received an email notification from O2 claiming that a request for a tariff change had been made. No request had been made by us. At first I put it down to some sort of [problem] email and ignored it, but checking my account online later that day, it did show up as a change of tariff - with the new tariff of £29 per month for the same 50GB i was already receiving. I chatted to a couple of gurus until it appeared 'Keith' finally understood what I was complaining about. He said he would change the tariff back but the next payment could not be stopped but he would make sure the extra charges were reimbursed soon after. I waited and waited, and nearly four weeks later I still havent received the refund, and my tariff is still showing as £29 per month. I dont know if it was the right thing to do but I have raised a complaint through Resolver, and am currently waiting for their response. As a side to this, one of their gurus told me the exact time of day the so called request was made, and I have prove through my vehicle tracker that I was driving at the time, and no one else has access. My suspicion is that O2 are running some sort of fraudulent [problem] once they realised they are not charging me enough for the 50GB. Shortly afterwards I noticed that an extra charge of £4.50 has been added to the account, stating an 'app' had been purchased from Globway BV. I had not, and never would buy an app for £4.50. Another complaint was raised about that. Then just yesterday (Sun 10) I noticed that an incredible (for us!) 7.21 GB had been taken from our remaining monthly allowance, with 2.78 GB going after the device had been switched off for the night. Another complaint ensued! This is now the second time in two months that over 7GB has been wiped from our remaining allowance, and I wonder if anyone else has any similar experiences of this, and if any members can recommend future course of action? Many Thanks