Paying for a non.functioning device for 20months

C.Track refusing to pay back my money. I`ve been paying C.Track for the past 20months for a device that has never worked, C.track installed the device and never activated their sim card in my car, I never got any sms`s or call from them for notification. They are unable to trace my car and they don't have records of it of which i``ve been paying for 2 years. I asked them to cancel my contract with them since the device has not worked. They are telling me that I will be liable to pay for the remaining 14months. They are asking me to rectify their mistakes but they don't want to pay me the whole 20months that I've paid for. They were able to start deducting money from my account without checking or doing the follow ups on their device for 2years.I am the 1st installer of the tracker they were supposed to explain to me how the device works, do quality check.The lady tells me about the terms and conditions in the contract of which they never send me a contract. They are forcing me to me to be in their contact with them.The only thing C.Track is interested in is my money I paid for a non device for 20moths and they still want me to pay for the remaining 14months for a device not working