unfairly blacklisted by Discovery

Dear South African, I am hereby sharing my *******ly blacklist that I am experiencing from Discovery Helath. To cut the story in short, I was permanent employeed by Cellc last year, and Cellc's policy is to have a Medical Aid with Discovery. I took the company medical aid (Discovery), last year before end year Cellc went to financial problems and I was retrenched and they cancelled my Medical Aid with Discovery. This year on the 30th January 2015 i received a call from Discovery stating I am owing them an amount R988, I made an arrangement with them that I will pay them 330 for 3 months, and also noted I might just pay them the full amount anytime but before 30 April 2015. Yesterday I called Discovery requesting for their bank details and settled their amount. today I called them requesting if the amount is reflecting and the lady who assisted me told me yes its reflecting on my statement and they will also update my record from ITC because I was blacklisted if for what I really dont know. Maybe someone from Discovery can explain to me...because this is really damaging my profile on that matter they should have inform me I was going to pay them as I did.