My understanding is that if this is a booking through a Travel Agent, then BA reservations have no ability to make changes to this booking this far away from travel date. Your travel agent may still have control of the booking and you should speak to them to make any changes. The booking doesn't transfer to BA control until much closer to the travel date.

Regardless, I think you need to speak to your TA urgently.

This is one big advantage of booking directly with an airline, the airline reservations agents have full control of the booking.