Personally I'd turn up at the office and not move until it was all sorted or some decent progress made. Its very easy to fob someone off with an excuse on the phone, but if they are sitting in your office, looking very pissed off, then its not so easy.
I know someone who did something similar with their solicitor, sale was being dragged out for absolutely no reason and the solicitor nearly lost them the sale due to incompetence, so walked into the office one day and refused to leave until the contracts were given to them so he could personally deliver them to the buyer.
Also gave the solicitor an earful when he eventually got the contracts and also informed him that he would be expecting at least a 50% discount on the fees. It worked..