Poor service from Telkom mobile

A few months ago I have taken a laptop contract from Telkom and unfortunately within a week my laptop was ****** from me during a break in. I did contact Telkom on numerous occasions to ask them what will be my options as now I will be paying for something that I don't even have. I even opted to pay up the contract in which Telkom uptill now is unable to assist in giving me a charge. This laptop has come with a modem in which I've never used. They have deactivated it and uptill now they are still charging me for something that I am not using. So I would like some assistance from them or else it can just go unpaid.