worst service

ive been a member of gym company since 2016. i had a platinum membership where i was paying R299 per month via debit order which always went through on 27th of every month, to my surprise on 01 March 2018 i get a call that my account is R1600 in arrears. when i called to follow up how and why that happened as they where supposed to be debiting from my account every month i was told that its been bouncing since december 2018, when i disputed that and told them there is no amount that has bounced from my account they said that no they are trying out a new system so maybe thats why, when i asked them to verify my account details they actually told me that there is no account details on their system meaning that they didn't load the information correctly, dont know how that is my fault but anyway now they telling me that i must an arrangement to pay of the R1600 coz of the mistake they made. they said they will get headoffice to call me so we can sort it out but i still haven't heard anything from them. Now im going to have a bad credit record against my name for something i was never informed about.