My elderly mother-in-law is undergoing cancer treatment at the moment and desperately needs her mobile phone for hospital visits. Talktalk are charging her an exorbitant amount of money for data and so after speaking to TT and being told there is nothing they can do we have requested to transfer her to O2. We have received the SIM card & PAC code and filled out all the relevant forms. Whenever she puts the new O2 sim into the phone it says “SIM not supported”, I contacted O2 today to be told that her TT mobile number does not exist and that to rectify this I must talk to TT, easier said than done as none of their phone numbers are working. Any ideas what I can do?