DLP is meant to prevent exactly this kind of problem, though as always the problem lies in the execution.

Btw, your S&P lawyer should have kept a portion of the purchase price (normally referred to as stakeholder sum, 2.5% if I'm not mistaken) as part of the DLP process.
In case such situation arises and the developer does not make good on it's responsibility, you can hire outside contractors to make repairs and claim from that sum of money.

And you should really read your S&P.