I have to pay EMA back?

Hi ok - I started college in sept 2010 and during the summer had signed off my ema forms so that the money was pretty much in there strait away. I got my first payment (�160) on 4th october, my second on 18th october (�60) I quit around end of october for personal reasons. The college then stopped paying my ema as i knew they would but i started recieving letters from the ema telling me i needed to send in the required information otherwise my ema would be stopped. Anyway, stupidly (i know that now) i ignored them thinking well im not in the college anymore and im not getting ema so why do i need to send info. Anyway, i got a letter this morning teling me i am required to pay back �220 of the ema i got during my time in college. Why is this? It doesnt say why i need to pay i t back - I was attending college during the time of payment so why am i required to pay it back??????????? Also I have bank statements proving i did not recieve ema from the date that i left college onwards. Please help :(