How very unfortunate David.
This is one of the reasons we do not accept payment in this manner. Another is the additional cost. I admit we no longer carry out pre-purchase inspections but when we did my view was that if the potential client could not afford the service out of ready cash reserves, given the deposit needed, the stamp duty and legal fees etc., let alone any additional specialist reports recommended/required, then did we wish to accept them as a client? We took a no view.
With regard to the bare faced cheek of enquiring if they can sell it on, I know my response would not be positive. I imagine in your terms and caveats there is prohibition to disclosure and the like and so you are within your rights to withhold.
I suppose on a without prejudice and liability basis you could contact ‘the client’ and suggest you could offer that permission if they withdraw the credit card stop and honour the payment due.
Regards,
Bruce Forrester