buyer changes from cash offer to lender in escrow.

[Anthony Hernandez]

selling undeveloped residential lot.  under contract, with a buyer for a cash offer, no option period.   6 days from closing received an objection letter stating they now have lender and they are objecting to survey that we didn't even have to provide. no 3d party addendum provided.   closing date was set in contract and that has now passed.  their attorney has not responded to the marked up objection letter from title.  looking for insight on options.