I think this would be the way I should have gone with this.
For future reference:
As my Phone Line with its number is down as cancelled it's unlikely I could get it transferred anywhere now so I'm giving up.
Were you told what the price was going to be for BT telephony without any BT broadband service ? you never said the price or if this was discussed ( you said that they confirmed you could continue with telephone only but you at what price ? ) if the price never came up , it’s not surprising that you lost telephony as well as BT broadband, FWIW , as you have broadband from Virgin , the telephone only discount for BT customers without any broadband from any provider wouldn’t be available so the saving would have been hardly worth the effort of removing broadband in the first place , in the order of £1-£2 a month .