Cancellation of Membership

I went to the southdale branch on the 9th December to cancel the membership & they said Thuli wasn't there so i left a note for her to call me back. She never called me back & i called the branch numerous times & no1 answered. I had to email Thuli after a week or 2 because i wasn't getting any response. Now they debited end of december which i didnt agree on since my contract already ended end of November and i wanted to make sure its cancelled on the 9th December. January they called me saying i should pay my for December 350 since it takes 20days notice. I agreed for them to debit on the 31st January. Now today i received a call from them telling me i should pay 600 and something which is a *******. I'm deeply frustrated with Thuli and Zone fitness, not even sure if she cancelled my membership with her poor service. Will warn people not to join this gym