rude teller...ruins my day

I went through to pay my rent on the 30th of June around 3 and as always they are understaffed and I was with my 14year old son at the time.At the teller he informs me we don't accept these slips anymore( my rent statement comes with a preprinted red receipt) and I reply\ but they insist I use that and I've been coming here every month including last month and the blond lady by the disabled side didn't say anything"then he tells me \""well everybody has been dining the wrong thing and I'm telling you the right thing cause I could make you go back and fill in the right one...dobyou think that's fair?\""I have never had anyone be so rude"