The other thing shops do in my experience is to print the receipts with ink that fades, ...
One of the things I got in the habit of doing when I got the equipment to do it is scanning all significant receipts so that I have a permanent copy. The scan never fades.
Another class of things with "disappearing ink" that can leave you without records includes the "self carbons" that some checkbooks leave as your only record. (Some banks that use these make it very difficult to get a copy of their copy, and with "echecks" they often don't have a record either.)
I've never had a seller refuse to accept a print from the scan instead of an "original" even though some say in their fine print that you must have the original. Most will do it just because they like to keep a good customer and I'm nice (if they do what I ask for).
In one or two cases I've had to say something like the (US) "Federal Paper Reduction Act Requires that a true scan of documents be accepted as just as valid as the original."
While I don't actually know that's an accurate quote, they've always bought it.
(Bullshit is a marketable product, if you're good enough at it.)