Virgin Taking my money, forcing me to pay rent as

I worked as Personal Trainer at Virgin Active. I had clients on the Team Pack system, that meant i get R1200 per person deduction from my monthly rent, once they have each done 24 sessions and booked their sessions on the Virgin Active System. I had three clients who did not book their session, even though I asked them to do it, every day. They never came for their last few weeks of sessions, and when time came to get my R3600 rent break, Virgin said no, I cannot get it, as they did not book their sessions. I therefore did not have enough money to pay my rent of R5742. I now owe the gy that amount. They have cancelled my contract as Personal Trainer, and when I tried to join as normal paying member, they said I can not join as member, until I have paid the R5742. I have written letters to the head of Personal Training, complaining about the R3600 situation. He forwarded it to the club manager, and she just never handled the situation,never even spoke to me about it. Virgin has done NOTHING to help me resolve the issue, they just force me to pay, and now i can not pay, and not even train at their clubs anymore. VERY BAD SERVICE!!! I have send email to head office but no reply!!