Entered me into a contract without consent

I took out a mobile contract with Telkom a while ago and pay my account via debit order. for this contract I pay R99 per month. This contract account number ***. Suddenly I get invoiced for a balance brought forward for something I never received, and I am being charged for a subscription that I know nothing of (Account number ***) I spoke to a representative that told me that they do not know why I have this balance brought forward, I was advised that it is for a wifi router... She also could not say why no one ever contacted me about it until now. I never gave consent to this contract, I never received any router from you, and I would like for this contract to be cancelled from my name. I do not consent to you taking this amount off via debit order and any such attempts shall be withdrawn. Please can someone urgently contact me regarding this invoice and cancellation and withdrawal thereof. If you are not able to contact me via telephone, then please send me an email. Regards Armandt Geldenhuys