The best way for DIYer to buy HVAC equipment and supplies if EPA 608 certified but not contractor

I'm a do-it-yourselfer who has three air conditioners that need to be maintained on the road. I have no interest in contracting-out my services to others. But I occasionally need minor AC repair items. As Murphy would have it air conditioning tends to break down when you need it most at which time it is nearly impossible to find timely service for my specific type of equipment. typical wait times for an appointment is one month which is not feasible when traveling. And even if you do find someone you're not sure they will do things according to the perfectionist standard you would prefer.

Therefore I studied for and passed the EPA 608 Universal certification. a certain major supplier with national coverage with the initials JS Supply in one state refused to sell me any supplies that might possibly be used to repair equipment. They said they would sell me any equipment just not supplies. I called corporate but received no response as to whether this was a national policy or not.

I would be happy to pay someone to do the work if I could find someone available and knowledgeable to do it relatively soon wherever I am, but long-term the most logical thing would be to maintain the equipment myself given the unique circumstances. That is it seemed like the most logical thing until the Absurd and unexpected response of a major vendor to the offer of purchase of their product.

how do I inquire whether a distributor sells directly to consumer without raising a red flag setting off all their alarm bells? I'm trying to do the right thing, and intend to be very conscientious about it.