Planet fitness - pathetic service

I signed up at planet fitness about 4 ears ago. I paid my tag fee and my joining fee and after about a month of queries on the phone and going to the club I still did not get my tag to enter the club to gym. I then told them to cancel my membership as the serice was disgusting! I recently recieved a years free membership voucher for planet fitness through a competition. They now refuse to give me the free membership because I owe them R12000 for the previous membership - which I had not used and due to frustration asked them to cancel. They thn offered me a discounted membership which I am considering but the service is yet again appalling! I have paid my tag fee on the 19-11-2015 and I am still waiting for my membership. I have been to the club 3 times now and no one can help me. I have given them my contact details 3 times and promises are made to contact me and they never do. I am sitting in the very same situation I was about 4 years ago. I can not believe it.