Deceased buyer after exchange

[Butterfly61]

I am buying a new build flat with the previous buyer passed away after exchange. I appear to be in the middle of a nightmare as agreed to use the recommended solicitors to facilitate for sale. However they are still acting for the deceased buyers final termination agreement. Therefore they will not tell me anything about why it is being so slow. The deceased family also have their own solicitor. So there are three solicitors, my one, the developer, and the deceased family. It has now been 18 weeks and counting and the agreement to terminate is the last bit. I would just really like to know why the deceased person wasn’t taken off of the paperwork back when it happened. Why does the agreement to terminate and my exchange have to happen some simultaneously????? Thankyou!!!