IMessage won’t accept using my phone number

[Ashman]

Recently had my number internal migrated from old O2 contract to my new O2 contract. iMessage now won’t work with my number and only accepts my email address. Been through customer service and had all the normal toggle on/off, network reset, phone number is right etc. Still won’t let me select phone number even though it shows and just gives iMessage activation error. Told to ring Apple who said it’s because I don’t have International Business SMS and the number can’t verify. O2 say everything is fine with them and go back to Apple. Going round in circles and stuck. Was working fine before migration on phone number. Any ideas before I get to complaint stage as already spent in excess of 8 hours going back and forth. 

[MI5 · Accepted solution]

@Ashman 

First thing I'd do is get a new blank sim either in store or by requesting one from O2, then do a sim swap Guide: Sim Swap: a mini guide 2017 update