I think you are being selfish. Your mom gave you a Christmas gift and she probably put some thought into it. Trying to exchange it for cash is rather tacky. You should have accepted the jeans and thanked her for them. If you felt you absolutely could not live with the jeans your mom handpicked for you than the least you could have done was take the store credit and obtained other merchandise at the same store your mom shopped at.
Speaking for myself, I have never returned a gift somebody gave me. Even if I didn’t like it, I managed to find some use for it.
OK, so I keep something I don’t want, never wear them and donate them to Goodwill with the label still on them.
They were basically mom jeans and too trendy for me.
I’m not trendy at all, but my mom is to a degree.
Thanks for telling me how to live my life. I appreciate it.
BTW, it’s the first gift I’ve tried to return in decades.