BT’s crossed wires over line rental refund

Its telephone adviser told me I would lose all my pre-paid charges if I cancelled my serviceIn light of its price increases, I contacted BT to cancel my service, as per the rules you recently reported. I was told that as the line rental and broadband are separate, if I cancelled I would lose my pre-paid line rental payments. I challenged this, but was told by the member of staff that BT is a big company with good lawyers and I would lose the money. Is this right? JD, by emailNo, what y