Hi, I hope you got it all sorted but here's my two penn'orth in case anyone comes across this thread as I did.
I doubt that BT rejected your port request themselves due to wrong postcode, more likely it was Openreach and their out of date database. I had a similar problem when trying to move from FTTC to FTTP with BT and keep the landline number - Openreach insisted we were at a different postcode from over 25 years ago.
In the meantime someone had built a dozen houses on what had been the drive up to our house and our postcode changed to reflect us being at the end of a new cul-de-sac instead of on the main road. It took over four months of wrangling back and forth, BT technical were terrific, BT sales were hopeless. But once I'd managed to figure it our and tell the Tech folks what the "old" postcode had been, they were able to nudge Openreach into the 21st century.
The problem is that although your contract is with BT, it's Openreach who hold the keys to the castle and do all the infrastructure work. They are literally not allowed to talk to each other, only to communicate electronically, It's madness.
