I was raised by a mother that taught me never to accept gifts too. It was a pride thing and something about airing dirty laundry. I still struggle with it. I wouldn't ask for help if I was down to my last crust of bread, no joke because of her voice in my ear.

I'm trying to be more gracious. It's not easy to undo a lifetime of learning.

That said, wow. Potatoes. Lots of them. I think that would have been okay-ish, if the rest weren't included. But wow, just holy rude and OMG! Some people are just awful, but to use a 'gift" to abuse a person in such a way is new even to me and I've seen pretty much everything.

You missed nothing. You did nothing wrong at all. This is all about them and who they are.