OP you started this thread back in September and I've been following you all the way through.
I agree with other posters that you should be looking into some kind of court order. This seems to have gone on far too long and you are still back where you began - with no respect for you as parents of your child and soon to be new arrival.
To me, the cut off would have been what they did for your daughters birth, but it has continued with her then birthday and now getting abusive letters demanding they have access 24/7.
I really think you need to make a decision ASAP. This stress is not good for you or your baby and needs to end.
Just my 2 cents but I really wish you all the best x