I have instructed my staff not to respond to "jerk clerk" comments like this, after we return the first fax signed. All subsequent faxes are trashed, phone calls deleted from voice mail.
We do inform the patient that their pharmacy, supplier, etc. is making it difficult for us to continue to care for them, and offer the telephone number if they want to help. And yes, some patients can be just as nasty to these services as they are to our office personnel.
By the way, the patients have usually already received the diabetic supplies in question, even before the fax returns with the doctor's signature.