Deduction

I took a loan with Nedbank and the agreement was an instalment of R2068 end of January I received a threatening sms about sending sheriffs although my account was paid the previous month, I then called the 031 number that was on the sms and spoke to the lady who said that the sms was for arrangements and that my instalment will remain as it is, previously I made an arrangement of R1500 for arrears, she assured me that that falls away and I'm required to pay only the instalment but end of February, the instalment plus instalment was deducted, again the same end of March although I asked so many times about the R1500 and was assured that it won't be deducted, this has been an such an inconvenience and I called Nedbank on this matter and was sent from pillar to post, Nedbank had no right to deduct my money without an agreement and therefore request to be refunded, after they took their instalment end of March they sent me an sms confirming the instalment only no mention of R1500 which they still deducted