Conveyancer ghosted us for 3 weeks — during exchange week

We were supposed to exchange contracts last Tuesday. Our conveyancer went completely silent — no response to emails, phone goes to voicemail, out-of-office isn't even on.

Our estate agent called their office and was told they're "dealing with a backlog". It's been 3 WEEKS. We're supposed to complete by the end of the month or our rate lock expires and we lose our mortgage offer.

The seller's solicitor is furious. Our buyer is threatening to pull out. The whole chain is on the verge of collapse because one person decided to disappear.

I'm literally paying this firm £1,600 and they won't answer the phone. How is this profession not better regulated?