I ordered via prime on Sunday the 13th and it still hasn’t shipped and it’s Wednesday. Where’s my package?

Suggest you consult Amazon customer service for more details

Are these bags machine washable?

No, they are a plastic material but you can wash them by hand. Although the package says washable - I would not put them in a washing machine. I think thy would tear. But by hand is no issue.

Will these fit on the back of a wheelchair? I'd like to be able to hang the handles of the bags on the back handles of my wheelchair. Will this work?

If the handles on your wheelchair are no more than 21 inches apart (measured from the outermost edge of one handle to the outermost edge of the other) this bag will fit over them. The bag has two handles. Put one bag handle over one of the wheelchair handles, and do the same on the other side. This bag is very roomy and the fabric is lightweight, yet sturdy.