WIFI OFF BUT MY ACCOUNT IS UP TO DATE

My wifi has been disconnected from yesterday apparently I am owing but I was given a reduced subscription for 3mnths. But Leila from billing says despite the reduction which worked fine last month I now need to pay what is outstanding from before my subscription was reduced. But I was on a month to month contract which was not owing. Pleasevhelp explain this to me. I was so HAPPY to get the reduced subscription while I sort myself out now I don't why I'm herer.