Where is my credit

So edgars please explain i have been paying my account for more then six months R250 to R300 a month so if we work it out to the highest amount R2100. All good last month i had R1800 credit to buy have not used account for how many months from December 2019 go and pay my account last month end R300 and see my credit available. R1000 what the hell is going on please explain i need answers now you are busy steeling from your people who is still actually are still paying.Fix this i want to know what is the story