Cancelation fees

So i requested to cancel my contract with Vodacom and then recieved the cancelation fees, now my contract is purely data only, and is R169pm (no device) and i have about 12 months left, i thought since its data only ill probably pay R400 or so, but they are asking for R1900????? If i were to keep the contract i would end up paying R2000. Is this fair? I mean in my mind i dont owe Vodacom anything, i have no device, no insurance and ive been with them for years. How can they be so ruthless, this is how hatred for a company is formed