Refund Refusal

My debit is R379 and R901 was debited on 25 October, I was told R522 will be refunded back within 24hrs it's over a week and I'm still waiting. Now I'm told R359 will be refunded. They don't tell me why. I asked to cancel the debit order the also refuse. When I ask to talk to the manager they still refuse. I'm still waiting for my refund