THREAT TO BLACKLIST AND ITC WITH A 15YRS PERSON

When I was 15 years old my step father signed us up to a planet fitness account through Discovery Health. Since then the policy was cancelled by himself through discovery and Planet Fitness. Now 13 years later, I am now 28 years old and have just received a call from Planet fitness debt collectors advising me they are turning me over to the ITC to be blacklisted as I owe planet fitness wait for it...R18500 rand. Not once have I received an email or SMS of a bill or statement from these guys for the last 13 years and cannot understand how they can bill a 15year old teenager who has never been inside their gym for an account. Due to this I will never recommend their services, nor step inside their gyms as they are *********** and blatantly rude, along with their hired debt collecting company. I am escalating this further and am not going to allow a corporate to treat people with such disrespect and dishonour.