Can I get a copy of a receipt if I know the date, amount and invoice #?

I have no experience in this area.

Not sure but if you have the scan and go app on your phone and use that for transactions you always have receipts and purchases

Depends on the store policy. Some stores do. Other stores do not.

I believe so at the service desk using your membership card. Might want to try online under your Sams account as well. Lot of info there