Will the contractor take the test?!

New York City:
--Kitchen remodel
--contractor asks for a $5000 payment
--customer opens safe, there is $28000 in cash inside envelope
--customer takes $5000 from envelope, puts it in another envelope
--customer gives contractor envelope, contractor leaves
--one week later, customer checks safe, discovers he gave contractor the wrong ($23000) envelope
--contractor claims to only have received $5000