See wiki article here on DME handling
"One users Path to machine
Here's my thumbnail sketch of how I got my latest CPAP/ASV blower:
1. I called my health insurance Customer Service, we discussed which DME's were in-net nearby, I noted names/addresses/phone #
2. I called above noted DME's to decide which I wanted to deal with, determined mostly by geographic location and products carried, AND by reputation
3. After the ASV version of PSG, I called the pulmonary docs office to tell them which DME to use for the ASV script
4. Called DME, doc, and insurance MULTIPLE times until my script was filled with newly prescribed ASV
5. Waited 24 hours and repeat step 4 then step 5 over for a few weeks
BTW step 5 has NO sarcastic intent; this is really what happened. I didn't sit very long while waiting on these 3 amigos to do anything. At least one of the 3 heard from me every day until I knew the machine was to placed in my hands on a certain date and time."
You can try that if the current DME strikes out in any way. IMO I don't give the DME too many chances as it's my health they're playing with.