Could I call the service desk or something and ask for the few items I need to be at the desk so I can just pay and go? My disability makes it very difficult to shop, even with the electric cart (if you can find one!).

If they don't, they don't deserve your business.

Call and ask ...

Use Instacart to have those items shopped and delivered.

I believe by law they have to accommodate any person with a mental or physical disability as outlined in Federal Disability Act

I'm sure the service desk, can accommodate that.

Give them a call, they may help you