@johnson Well, eventually you are sticking them financially because the payments do stop in the end and they have lost one customer for good. If you have agreed to pay them a certain total amount in instalments effectively, then the money is already as good as gone. But you do not give them any more than that already committed, they lose out every year until the day if doom, so I think my point still stands, but yours is well made.
I would not put up with the annoyance just on account of a bit of money because I do turn into Mr Angry sometimes, but we are all different.
@jelv good point! And you can write them up at ISPreview saying what your experience has been, and why you left, if you did go that way. As well, there is also a forum at the ThinkBroadband website with a re PlusNet section and an “ISP-unhappiness” section, so both ideal.