I recently upgraded my phone to a secondhand unlocked iPhone 7, with the intention of using my existing SIM. Whilst setting up however the phone locked itself to the carrier 'Virgin 35.0' and has reached a point where set-up cannot continue as the phone produces an error that the SIM is not supported 'under the activation policy currently assigned by the activation server' and to 'insert a SIM card from a supported network or request this phone be unlocked by your network provider', even though the phone locked to the carrier and is itself a virgin SIM.
I called 789 numerous times without much help; the phone has been factory reset numerous times, as well as the SIM being swapped with a new replacement without any luck, and was told that it cannot be unlocked on virgins end because the IMEI wasn't available to unlock on their end, even though the phone has now locked to them and there is no offered alternative as to who to ask.
I have previously purchased and swapped over phones for another person under my account to the same unlocked model from the same supplier without issue, although that is set to the carrier 'Virgin 32.0' (which might be the issue on the most recent phone?).
I'm just confused as to what to do now, as Apple wont unlock it and it seems to simply be a game of passing the responsibility to others without any other guidance, and I'm not willing to pay to do it elsewhere if the issues simply going to reoccur.