blacklisted after payment

i have a problem with this gym company they blacklisted me after paying my penalties this month,yet they never notified me about my account having a problem which i wasn't aware of. So on the 27th March i went to the bank to check what went wrong and i found out that they were right my account was blocked for them but the bank consultant showed me something i wasn't aware of about this gym.They debit using different names thats why i blocked it cause i dont want to loose my money on debits i do not know and apparently i wasn't alone with this kind of matter on that day. So big question is why didn't that company call me or send me a letter to inform me about the debit order not going through otherwise they sent me a letter giving me 20 days to pay before they blacklist me which i went to the offices at Maponya Mall and spoke to Fikile which i wasn't happy her response to my concerns. Now i want they to clear my name off the credit listing cause now cost me a lot my home loan has been declined because of them. In business you do not running and bkacklist people without communicating with them effectively find out what is the matter with their late payment and advice them to do so.