party wall agreement problems - please help

[Lola11]

We are planning to build a new extension and our neighbour had appointed a surveyor who was their personal friend and who had done some work on the party wall agreement 6 months ago, charging very high fee. We did ask them to change to someone else as the fees seem to be very high and demands excessive (in comparison with the neighbour on the other side) but they insisted that that we work with this person. We have changed our plans slightly since and have recently send the requested outstanding documents to the company hoping to continue where we left off (the end of it just requiring signature) but the company ignored all our attempts to talk to them as this surveyor is no longer working for them. Our neighbours have now appointed a new surveyor who will have to start from scratch duplicating all the work (and the coast). Worst of all this would delaying our work by several weeks and our builder is not going to be available any more. Do you think that we should pay for all the work again or do we have any choice? Any advice will be greatly appreciated!