My mortage company raised my monthly payment plz help?

i filed to them to lower my monthly payment in december and they just now looked it over n called me in august and the month before my mom brang me on a cruise and i bough my son some things so insted of lowering the monthly payment they raised it to $1,400 and thats $400 more per month and i cant afford this so now im going to get no extra money per month and i will have to buy fewer groceires...can they do this leagly....plz plz help