another wrong debit

I don't understand how FNB loans deal with they debit order systems. I got back my refund of R2950.10 , but they took R200 for their monthly arrangement on tge 15th Feb instead of 15th March which I was ok with. Now I wake up and they deducted R1375.81 on the 16th Feb which was not arranged by anyone. Now I have to wait again for 2 weeks to get my refund back because they always have excuses of how many working days or working hours to wait for refunds. This is such an inconvenience because I'm unemployment and survive on the little that they are taking!