MY NET DISCONNECTED

Am no more connected to the net, two days ago i was disconnected by the service provider for not paying the net fees, more so i was surprised by the amount they claiming. The first time they installed the net i paid for three months in advance since that was the requirements and later after that period i will be paying for monthly fees of which i agreed upon, i have been using normally but onething i didnt noticed was after the three months ended that i was supposed to pay in the office but never did so. the system is totally different and am caught in da system, i thought like they will disconnect after the first month of the expiry date rather they did after three months and now owing me almost 40$ for this period, i dont have that money right now since i spent all my expences. at the end month i will be connected again nd serve this mother fuckin hudas. anyway am fucked up by this system.