I just got thru to Testors. They didn't ask my name so you don't have to call. If you like the number is 1-800-962-6654.
This is what I was told:

Mail the Airbrush Body only to:

Testor Corp.
440 Blackhawk Park Ave
Rockford, Ill 61104
attn: Customer Service

Include a note as to the problem you have.

They recommend sending by Certified Mail, UPS, of any way you can get a tracking number.

HTH

Chuck