I feel for you, OP. I am so tired of the entitled, spoiled attitudes when it comes to gift giving.
I have a relative, an unfortunately close relative on my dh's side. She's nice "enough," but has been spoiled by her parents and especially one particular grandparent, hence why she will be called "SB, for Spoiled Brat in this story. In his family, that level of relation has an expectation of gifts. SB has always wanted to learn how to bake, but didn't have any equipment. SB gets engaged with a date set 2 years hence. For over a year and a half and with SB's mother's knowledge and approval, I assiduously collected good--high quality bakeware because of course, only the best would do for SB! I collected them when I found them on clearance, piece by piece. I accumulated an excellent collection for a burgeoning baker, along with 2 classic cookbooks.
I get the shower invitation and noted the "Cash preferred" written on it. I did not read that as "Cash only" and sent off my gift (which cost an arm and a leg to send, btw). After more than 2 months had passed, I called to make sure she had actually gotten the gift as a little nudge. She sighed and said, "If you're expecting a thank you note, forget it. You didn't give me what I wanted -- which was CASH! Can't you read? So no thank you note for you!"
Needless to say, I did not attend nor give her a wedding gift. She had the gall to call up and ask me why. I told her, "You didn't give me what I wanted -- which was thank you note. So no wedding gift for you!"
She's no longer speaking to me. I can live pretty blissfully with that silence.