Telkom wifi router data bundle has become a nightmare after a year of using their product

I went to Telkom shop at rosebank to buy the wifi data router last year August, 2017. they had the uncapped special, but when I got there they told me the area that I stay at does not support the uncapped product, which i now find strange as most people are telling me that is not true, however I was persuaded to take the deal that charges R 750 a month (24 months), as the person who was assisting said the data lasts and will not even have to use my spend limit and said I can stream however i want.

Since i took the contract last year, I have been happy, the data was lasting, i even stopped using my dstv as i was watching and and downloading everything i needed online, everything was good until this year in July, where for the very first time I had to use my spend limit because all of a sudden my data got depleted before the end of the month (very strange). The following months after I've been trying to save and not stream too much, using night data to download. I do not over use the data as I'm always at work and sometimes I am not even at my place at all and it has always been like that, but still in the middle of the month as this current one my data are almost finished, I have to stop using as I dont want them to finish before the month end. I feel unhappy now with the service than i was a year ago. I used to even tell people about how good the telkom wifi data bundle router deal is, but now I'm so disappointed, the service is a shame compared to what it was a year ago.

Yesterday, 21 November, I try to get assistance, from agents, using the telkom mobile app on my phone so they can check for me on what is really going on with the data, because I cannot live like this, the service they had promised me is now very poor, I am not happy at all, however, i got disconnected so many times every time I tried typing in my issue, and when i finally did, i was told they cannot assist me due to technical problems they were experiencing and was asked to try at 12 midnight, when i did, i was told to try again at 7am, when i did, the last agent told me they cannot assist me, I need to stream less to save my data.

I decided to call customer care to find out about the steps i need to follow if i want to cancel the contract, as i cannot continue paying for a product that I am not happy about every month, unless it goes back to how it was when i started using it a year ago. The lady told me I'd have to pay for the remaining months (which is about 10 months from now) including an extra R 800 for the cancellation. I find it to be so unfair and unreasonable, because it means I'll be paying for all those months, but not even using their service, I'll be giving them money for free. where is the sense in that?

The person who sold me the product told me that i could cancel the contract anytime should i not be happy with the service as i was doubtful at first. I remember he even said they would just collect the device and stop uploading data, he said nothing about paying for remaining months.

All i want is for the service to go back to what is was a year ago (may data lasting the whole months), before July this year or if they cannot help me with that, cancel the contract without me paying for the remaining months as i will not be using their product anymore.