Wheel of happiness my foot ?more like wheel of doom

I won a free month and a free upgrade from their rewards and now all of a sudden I am expected to pay almost double my monthly subscription.

I won the upgrade in March but was upgraded in April and then in May when I asked how much I need to pay I was told I don't need to pay because I have a credit and I asked them to check twice but still came back to say I have a credit and they didn't debit my account.

Now 2 months later they coming back to say I must pay, the system credited my account twice but I used the money already. Where must it come from 2 months later, who has R829 lying around 2 months later. They credited my system so they must sort it out. I'm being told I must make an arrangement for the payment. I ain't making no arrangement their system error their baby to take of. They must just clear my account thats it.