Over-charging and Bad Service

I took out a two year contract with Telkom in 2016: The package was for an LTE Router with 50Gig Day and 50Gig Night Data at R699 per month. Once the data is depleted, the connection is cut and you're not able to browse, download or update any devices. For the past two years I did not upgrade or change this package in any way. Now, your company is saying that I over-used the data and added a additional charges. I NEVER TOPPED UP DATA ONCE IT WAS DEPLETED!!!!!!! The two consultants couldn't tell me who or when the package changed. They've told me that it's now set to automatically run past the 50Gig data at an additional charge. No-one is able to tell me who or why this was changed because I certainly did not activate the amazingly horrible service. If I wanted more data after the 50GIG was depleted, I would have done so. Just FYI, the data does not last for a month so I find it very strange that you could be OVER-CHARGING me and saying I use more than the amount of data allocated when by the 20th I'm not able to use any internet. Lets talk about your app - I have lodged 3 tickets querying this with no response. February 2018, today you've debited me R1657, January 2018 you debited me R1300, December 2017 you debited me over R1000 and November 2017 the same. Your call centre agents were of no help. Your Facebook chat doesn't respond so I'm not even able to cancel this dumb service. Let's talk facts - I signed for 2 year contract which gives me 50Gig day and 50 Gig night data at R699. I haven't topped up during this 2 year period. You're overcharging me for a service that I could get somewhere else for a fraction of the cost. Your staff is *********** because they can't assist with this error and you basically suck at what you're doing. Then you have the audacity to send me further promotions or the amazing other products you have available - I would NOT RECOMMEND TELKOM to ANYONE!! If anyone is manning your social media platform, they will see this; if not, it's falling on deaf ears. Push comes to shove, I will reverse payments and change my bank account details so you ******* won't be able to access my account any longer. This has gone on for way too long.