I've had the same problem with supplies for my CPAP machine. And the company that starts with an A...Apria, does NOT have nationwide coverage. By that I mean, each office is different and you have to set up an account at each one....and that takes at least 1/2 hr. BUT, this last time I tried to get supplies...last month (first this year), I was told everything had to be shipped. That was BEFORE they found out my ins. company. No longer can go into their office. Might be (should be) different for oxygen.
Advice....carry a prescription from your doctor ALL the time. Do not let them take it from you.....have them make copies.