I started to write something similar yesterday, and then deleted as it sounded snarky, but i do think re:
I honestly wouldn't rely on that, not even from your own solicitors, and especially not from the estate agent. We ended up phoning the other side's solicitors, making sure they were in the office, and getting the direct dial, and going back to our solicitors and saying PHONE THEM NOW, because he was phoning once a day and just shrugging if they were unavailable. No checking when they would be available, no asking who was dealing with the file in their absence, no followup phonecalls unless we asked. Absolute nightmare.
At one point I ended up saying something like "Phone them at 9 o'clock opening, and every hour after that if they're not available. If you can't reach the handling solicitor by 1pm, then immediately escalate to the supervising partner at their firm." because OUR OWN solicitors were being so shit. Reading that back, I think I will go ahead with the complaint I was contemplating, actually.