Electrostim Medical Services (EMSI) review: Avoid

My pain management doctor suggested a TENS unit and told me "It wasn't going to cost me anything." I agreed after pointing out I already have a nerve stimulator installed in my spine.
A few weeks later the TENS unit arrived and I just put it in the closet. Two weeks later I received a pack of the pads that the TENS unit uses. Two weeks later I received a back brace that I just donated to Goodwill.
2 months after receiving the TENS unit I receive a bill for almost $40, $28 of this being the back brace. The bill stated that if you are part of a QMB program to call them and let them know because then you don't have to pay these fees. I look up QMB - The Qualified Medicare Beneficiary (QMB) program is a type of Medicare Savings Program (MSP) that allows beneficiaries to receive financial help with Medicare costs from their state of residence.

A Qualified Medicare beneficiary gets assistance covering costs like deductibles, premiums, and copays. However, recipients must meet all criteria to qualify for the program assistance.

Since I am enrolled in a QMB I called to let EMSI to let them know only to be told that that isn't what they mean. They mean dual coverage or the QMB Plus program. That isn't what is stated on the bill, but whatever. I told her to stop sending me anything because I can't use the items. A back brace or anything tight around my abdomen would put my pain at a 10. She starts to argue about me having to pay the 10% the insurance didn't cover and stated that my doctor requested the TENS unit but not the brace. So you've sent me something no one asked for while collecting money from Medicare for it and expect me to pay the rest?
Even though I told her to stop sending me anything, 10 days later I received another envelope, which I've returned. I've sent a check with a note stating I am no longer interested in their service. Not sure how many times I'm going to have to tell them to go away. They already collected money from Medicare for products that my doctor didn't prescribe. In my opinion, these are the kind of scams that Medicare should be cracking down on - sending items to people they don't want or need just to collect money from the insurance (or the patients) is not good customer service. They should also be clear on what programs they are referring to on the billing since health insurance in the US is a disaster.

I have attempted to use the TENS unit but it is not as helpful as I need it to be.