I have asked a moderator to provide assistance, they will post an invite on this thread.
They are the only BT employees on this forum, and are based in the UK.
Sorry you've expereienced these issues on cancelling the second sim.
I can see you're expecting a callback tomorrow, in the meantime if you send us in your details using the contact the forum mods link in my profile, we can help if the complaint continues.
I would not contact Customers Services. You would be best to wait for the moderators to help you.
If you have replied to he moderators as per their link they will get back to you when your request reaches the top of their work stack. It normally happens within 48hours but they are busy at present and it is taking a bit longer.