I've reached the 100 limit of blocked numbers. It would be a straightforward change to the BTcall blocking system to increase the limit to 200 or 300 or even 500 numbers per user, and not take a lot of additional storage.
It is really fiddly to follow the voice menus to remove a number so that the additional (latest) one can be added.
A question for BT - can you please increase the threshold for blocked number storage? If not, could you please explain why you are not prepared to do so.