Why have you black listed me Jet?

I actually don't give them any stars, they don't deserve the one star. I was retrenched from work in 2011, I had account protection with Jet and I went to claim. I was given a really hard time by Jet until eventually I thought the who issue had been resolved. I have not heard from Jet since 2012. Yesterday I went to apply for credit at a financial institution, the application was denied because I was told Jet has black listed me. I don't know why they have done this worse so, without my knowledge. I'm trying to contact them but I'm being sent from pillar to post. I really regret ever doing business with such an unprofessional company.