Appauling service

I joined the gym last year November and they didn't debit my account that month. December as well...when I got to the club I was told I owe R399 for December. I get to the club today and they don't wanna let me in because I owe November. Its not my fault that they didn't debit. Worse they didn't pick it up for two months. After two months I'm told I owe November. It's a system glidge and I wanna gym. They will debit or I will pay that 199 month end. Otherwise will move on...I'm not spending a month without working. I need solution ASAP