listed with bad debt written off

I have been listed with a default on my credit report with bad debt written off- but let me explain<br> <br> 4-5 years ago i joined a gym called winchester hills sports club, i stoped training there also about 3 years ago after freezing my gym account due to me being unemployed!<br> <br> i never heard from them again and even thought they dont exist anymore! only to find out recently that i have been listed with a default on my name by a company called gym company pty ltd! i did not even know who this company is, when i put some investigation in place i found out that Winchester hills sports club has changed to gym company. but the fact is that i never heard from either company in the last 4 years and my address has never changed! i have been living at the same house for 15 years!!! <br> <br> i think this is ******** as i never received any correspondence from them regarding my outstanding debt NOR did i receive any correspondence to notify me that i will be listed which is a requirement BY THE NATIONAL CREDIT ACT!!!<br> <br> i will not stand for this incompetence! people think they can just list you left right and center without being educated!!!!