Vitality debit order

I have been a loyal Vitality member for over 10 years paying a month premium. I had changed the Vitality benefit to be linked to my Discovery group life policy. December I moved it back to Medical aid and upgraded my plan so I was out of sync of the premium and it should have been debited, which should have been grouped together. Spoke to someone on the 31st of March that confirmed that all was good and premiums are up to date - ref *** Then I get debited R1600 + on the 2nd if May ,called on Thursday to find out what this is all about and why the debit, was promised an email by the end of the day, heard nothing. Chatted to someone on Friday via whattsapp and was told i will receive a response... still nothing - ref *** Whose going to pay my bank charges for not having enough funds in my account? I cant afford that value to be debited once off for an error that Discovery has made.