Anyone have a number?

Reservations refused to give me one.

Basically my family are travelling on two separate bookings due to different return data. We are travelling outbound together.

Because we have special needs (Bassinet), my wife, baby and son (booking 1) have been seated in 54FG with bassinet.

I am ticketed in 43K.

I can't change to 54E because it's blocked by the airline (also a bassinet seat). Ideally we'd sit in 31ABC or 31HJK.

Is there a way to resolve this?

I'd prefer not to have to do it at the airport (the flight is 18:30 tomorrow from LHR).