Service increase without my knowledge and double charged

I have been a loyal customer for 5 years, I don't understand how did i end up being overcharged and double charged. I have 2 subscriptions Rainone unlimited and the off peak one, Rain one from R595 to R940 how did I end up charged that as I have never upgraded any services I'm still using the same services as for the off peak one I'm double charged now. I have called the call center numerous times no one got answers for me they keep on saying they will escalate to the relevant consultants. On the the 1st of June I paid according to the statement that was sent...on the 5th my internet was cut off being told I'm owing R1200 I asked the lady how did I end up owing she said it doesn't appear on their side that I paid. She advised I should pay R50 my internet will be back i paid now I'm owing R1200 as it appears as Promise to Pay on the app. How did I end up owing sooooo much as I've been paying my account time and what's due. Next week it's pay day how will I pay for services that I don't know how i ended on that amount.

Rain please sort this out or you will lose another client.