Data Cut Off with No communication from service provider

Over the past few days i have experienced worst experience from Cell C. I have a data Sim since 2016 which i initially took at 10G 5G day/ 5G nite. 2 Years later i upgraded and to a 20G 10G/10G. Yesterday i received an sms to say my all time data has exceeded. I usually exhaust towards month end however only to be told when i called the Call Centre that 2 years was up in December 2019 therefore my contract was reversed back to 5G which i initially took back in 2016, needless to say, no advise or communication from the service provider.

Good Bye Cell C, I have closed my account!!!!!!