my phone number won't connect to iMessage or FaceTime

Hello,

My FaceTime and iMessage are connected to a number that I don't know on my phone. When I bought the phone it was brand new, so there are no chances of the number being of a former owner and I've always used the same number and carrier.

I have tried signing out of my apple id, resetting my network settings, changing my Apple ID password, just switching off FaceTime and iMessage, but nothing works.

I have the right phone number on my contact info and everything except for iMessage and FaceTime.

Can anyone help me fix this issue?