You can consult the operation manager of valet facilities to resolve the issue. If you find major damage then you must have to consult your insurance agent for initial survey or you can also get coverage from the valet authority.
I had a bad experience last year while I parked my car at one Valet facilities, my car get scratches on the body. I don’t know why it was happened. I registered a complaint against valet facility providers to recover the damage but till date I cant get it reimbursed.