If its not a BT number then it is allocated to another provider. Openreach don't actually have any numbers allocated to them as they only provide engineering assistance to the providers that pay them.
The chances of getting your number back are slim, as if it does not belong to BT in the first place they cannot recreate an account with that number on it to make it active.
It all comes down to correct procedure. Do not give notice to your old provider (except in regard to TV services). Porting synchronisation & closing of the old providers phone account is the responsibiliy of the new provider.
Virgin BB TV Landline. Freeview/Freesat HD, Virgin Mobile, Tesco Mobile. Cable customer since 1993
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