We pay a monthly fee to have access to a card we c...

We pay a monthly fee to have access to a card we can use to pay our medical expenses. This is for convenience. However, we frequently get requests for extra documentation. I can see where this would be necessary if it isn't clear what we were paying for, but when it's a pediatric dentist, I think that's pretty obvious what we paid for. We obviously weren't buying milk. In the past they've said it's random which expenses have to be verified but when it's the same dentist over and over again I find that hard to believe! Why am I paying for the convenience of a card if I have to verify the charger with extra documentation anyway? Rip-off. Frustrating. Wish we had another option besides just paying after taxes.

Edit after company response:
Yes, we submitted exactly what was asked for. The documentation had exactly the info needed and yet, it's still not good enough. The rep on the phone today said the audits are random. I call bull. Never are the audits on my dentist, on a regular doctor, on an eye doctor, chiropractor, glasses company. They are only when we take our kids to this dentist. The rep said they want to make sure we aren't getting something not eligible, like teeth whitening. Really? What idiot gets their kids' baby teeth whitened? Goodness. I'd rather pay extra taxes and not use flex spending than work with this ridiculous company.