Bad service

Telkom is not assisting me in terms of cancelling the Wi-Fi router. Last month I sent an email regarding the cancellation and they rep**** saying that they acknowledge my request. Soon after that I noticed that they hadn't switched it off and they sent me an invoice and saying that I should pay the double the amount they usually pay.I have been trying to contact them regarding the Wi-Fi router but they've been taking me from pillar to post with no assistance.