Upgraded without my permission.

I had the worse experience ever with dstv. On the 20th of January i paid my account and downgraded via the WhatsApp app from compact to access. I received messages saying that i have bow been successfully downgraded. On the 2nd of Feb whebn i wanted to pay. It showed i must now pay R500. I called them asked them whats is happening. Thwy told me that i have upgraded to premium. I send them an email with attachments of the WhatsApp chats that stated i am downgraded. How i got to an upgrade only they know. I have been struggling since February to get them to sort out rhia problem. I have been finishing my airtime after them. I do not know what to do anymore because i refuse to pay for something i did not ask for.. Please help me Heliopeter. My client nr is ***2.