Credit amount to be paid back

Good day

On the 12 December 2018 I have settled my account with Direct Axis, on their statement send to me the amount was showing as paid with a credit that was due to me. I have struggled for two weeks to get this sorted out. On the 28 December they deducted my installment of R1784 from my bank account. I have phoned them on the 28/12, 31/12 and on the 4 Jan to request that the installment that were deducted is paid back into my account, without any luck. Their service is poor, they are quiet eager to take your money but when they have to pay it back you can wait until it suits them. I will never refer anyone to them.