Termination of Mobile Contract

Good Day,

About three weeks ago Telkom mobile made an online promotion which one qualifies when signs up for the contract. I initially asked the sales department whether it was true before I signed up which they affirmed that everything is true.

The contract for for data which came with a router, upon receiving it was then actived. Few days later to my shock my data was finished, knowingly that I have 100g of data i knew it was not possible.

I called and they said its a technical error but will be solved. I waited for long to a point i had to buy my own data while their sorting out the error. My final decision was to cancel the contract because i was not given the product that i was promised and having unnecessary high expenditure. The sales department have been playing cat and mouse games with me one after another stating they contract has been terminated while its not so.

Please assist with the above