Went out of my way to try and give dc1 a nice birthday despite being a single parent, one income, no financial (or otherwise) support from ex.
Couldn't afford a party or day out but my Mum is paying for a cheap hotel at the seaside at Easter so they aren't missing out.
As it was a kind of milestone birthday I bought a keepsake gift they would like and then spent a small amount of money on cheapish items I knew they would really like and use plus one of those take out meals from the supermarket and a cake.
Dc1 came home telling me all about what nice things had happened at school. Lovely but no sign of thanks for anything I had done or got for them.
Dc1 lost some sweets in their room another child gave them and had a strop then started talking to me like utter crap, tone of voice, sniping at me, pulling a face when I spoke as though I was stupid.
Twice I warned
Dc don't talk to me like that
Dc I don't want to shout at you on your birthday but you need to stop talking to me like that.
The third time I told them off properly. They went into a full on strop shouting how awful I was, how mean I was, how I had ruined their birthday and how dare I tell them off on their birthday and I had ruined it and they were going to tell everyone how awful I was. I said ahh well at this threat and was told I didn't care about their birthday and had proven it.
This morning they have told me they are going to tell everyone at school how I ruined their birthday and how awful I am because it's the truth. 
Apparently I should have let dc1 talk to me like crap because it was their birthday. 