I feel your pain as going through a similar situation with my parents. Can’t get anyone in BT to give me a definitive answer, on the phone for hours, nothing still sorted, tired of trying to clear security Q’s even tho I know all the answers ! In the end... be told your not the account holder so can’t do nothing. Tell BT advisor account holder unavailable due to loss of mental capacity.
However, investigated myself only way round it I think is applying for PoA. See details of PoA for what next process to do
