nag 'n brag
You complain about something you paid for, get a free thing or a discount, and then you act like you're a big shot and tell everyone about it.
I said my airline lost my bag, got a free drink, and now I tell everyone I'm the airline hero.
I ranted about my haircut, got a free trim, and now I say I'm the hair god.
I yelled at my waiter for bringing me the wrong food, got my meal free, and now I brag like I'm the restaurant king.