@Almee+Allen-king this is all a bit contradictory for us to understand properly.
In principle, if you've switched to BT, and BT have carried out the switch correctly, they will have instructed Sky to cancel your broadband contract with them. Because you're billed in advance by Sky, you may have paid beyond the date your service with Sky actually ended. That will result in a refund which will show as a credit on your Sky account.
If you have no further services with Sky (such as Sky TV) the credit will be returned to your bank via the direct debit, normally within 6 weeks. If you cancel your direct debit, that can't happen and you'll need to request a cheque from Sky which will take much longer.
