texting from one phone reply going to old phone

[Suegd]

I have two Samsung phones with a new contract provider for one. Pac codes took an age to be applied successfully. New phone has old number confirmed by contract provider but sending text from new phone means reply goes to old phone and nothing is received on the phone where txt originated. Can anyone explain what has gone wrong and what to do. Thanks

 

[hang-the-9]

Are you using a 3rd party app for texting that is still signed in on the old phone? If not, then you need to work with the service provider to fix this, the SIM card and their service is still crossed to the old phone.