Quite a few people get caught out by these hybrid bays, where there is a sign and a marked bay with a yellow line by the kerb. The yellow line is meant to alert you that there is a restriction outside the hours on the sign. Normally there would be a yellow sign at the top of the pole with the "No Waiting" sign, plus the days and hours restricted, placed above the parking sign. However, this location may well be in a Controlled Parking Zone, so I suggest you look on the TH website for a map of their CPZs.
One could say by not having the yellow sign at the top, they have failed in their LATOR Regulation 18 responsibility, but arguments like this usually end up at London Tribunals. Submit reps anyway, point out your are a BB holder so would have been exempt from the yellow line, and your total parked time was well within the time allowed.
