I wasn't aware the V6 remote could control a BT box 🤣
Have you tried to reset and re-pair the remote via the TV settings?
Unfortunately you need the TV Faults option when dialling 150 from a Virgin landline, or 0345 454 1111, but best to call at 8am to avoid call queues
You could also try the text messaging service. Just send a text with a description of new remote to 07533 051809. Your message will go into a queue and a representative will respond to you as soon as possible. It may take a few days.
For now you could download the TV Control app and use that until you receive a replacement remote