ALL SALES FINAL!
This store has at least 100 placards that read ALL SALES FINAL plastered all over. The store manager apparently got ticked off at people wanting to exchange cards and over-reacted. Anyone who puts ALL SALES FINAL signs all over a store is demented. It's a display of hostility toward customers that permeates the entire operation. You will not be treated kindly here. Go elsewhere.
If you're looking for a simple birthday card, Hallmark is probably the worst provider. They have a zillion unfunny humorous cards. They have the cheesy cheapo cards. Go ahead and announce you're a cheapskate by giving a card you paid 99 cents for. Then there are the excessively corny cards for your aunt, cousin, sister-in-law, babysitter, or income tax preparer. The cards are artless, uninteresting, and uninspired. You have to pick through dozens before for you find one you aren't embarrassed to send.
This awful shop's sale to me did indeed prove final, since I will never return. I would rather grab a card at Walmart. Try the grocery store next door. Trader Joe cards are nicer than Hallmark.
For a tasteful selection try Dick Blick, Whole Foods, or Barnes & Noble.