Hello. I upgraded my phone on 22/12/15 and I did it face to face in an o2 store. I discussed with the advisor the tarrif I wanted and it seems she clicked the wrong one and I have signed the contract for the wrong one.
I just checked bank statement and realised that I am paying £37.50 a month for my phone but in the store I discussed and said I wanted the tariff that was £33.50. I can't seem to get anywhere with this as they say that I agreed to the tarrif when I signed the contract but when I signed it there were no numbers on it and I assumed it was the tarrif that I said I wanted. What can I do about this?