Impossible to stop contract

My 2 years on a data contract (R500 for 20GB) is done, now I want to stop it as there are cheaper options now. I cannot go to a store as I am 110 km away from the nearest store and just cannot get off from work now. I cannot call customer care as I need to put in a the phone number of the contract sim just to talk to someone that is not a computer. I do not know this number as I have only ever had the sim in a modem. Tried sending an email but to no avail also as the reply to that was asking for the sim pin instead which I also don't know. The day the contract was sold it was no issue that I was so far away from the shop and everything was handled easily on telephone and the sim was delivered by Courier quickly, why must the stopping of the contract be such a big issue. And please put in a option to just be referred directly to a human person when calling customer care.