Depending on the state, you can file a complaint. That "may" get his attention....Who ordered the appraisal...? You may be able to delay payment until you get a call...
Texas link: The Texas Appraiser Licensing and Certification Board (TALCB)
It is specifically prohibited by USPAP and new HVCC rules for the appraiser to talk with even the homeowner about the reuslts of the appraisal. The only person the appraiser can communicate with is the client (that person/entity who ordered the appraisal). Yes, ultimately, the borrower pays for the appraisal in closing costs. However, the client is defined as whomever orders the appraisal.