This is something that Yorkshire men say when they can;t be bothered explaining something or when they give up a conversation half way through. Especially common with people born and raised in Bramley.
'So I'll explain to you why what you did was wrong.'
'Okay, so tell me'
'Well you said, oh it dunt mata'
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. PenguinBooks,1992. p. 38)