If you migrated to BT from Sky, as both use the same Openreach ‘connection’, then no home visit is necessary , the work required is done at the exchange ( that work is still being done ) so the question is why , if the Sky service has stopped, hasn’t the BT service started in its place, it could be your Sky service has been turned off by Sky, but a Openreach haven’t yet done the exchange work ( like a lot of company’s that are still at work, many staff are not ) so perhaps soon the work will get done, or the work in the exchange has been done, but something has gone wrong, or, you had ordinary broadband with Sky ( exchange based ) and are getting FTTC with BT , and that requires a visit to the cab as well as a visit to the exchange.
The ‘India’ situation as I understand it, could affect number portability , but that may not be the case...although difficult to get through, have you contacted BT as enquired what is going on ?, there are BT Mods on here that may offer to help, but in the current situation, solutions make take a while.
