Debid order for cancelled items

I wanted to order something on takealot using payjustnow. The order was cancelled. And now ther is a debit order going off my bank account for something i did not buy. Countless effort contacting payjustnow, nothing happened. No answer when you call, they dont reply via contact us, they dont reply to emails. This is very very bad from them. How do i pay for something i did not order and did not receive?!