Cancelled within 7 days but no refund

I'm fed up of calling rain for my money that they owe me. I bought their router package and cancelled within 7 days because of connection problems despite that they had said my area was covered. They collected the router and still deducted the next month and the next instead of refunding me as per contract. I've had it with their customer service and now I know that it isn't just their network connection that's poor but they are whole service is messed up.