Listed on Credit Bereau For Account Fully Paid Up

I have several Rcs Accounts all were on Debit order and was bein paid monthly,strangely my Dion Wired acc had problems debiting acc, every month i would get a call saying my account was in arrears, we tried changing debit order dates but still no avail, every month i had to do a manual payment for this account, finally when i was out of action in hospital for a few months, when i checked up on my finances after getting well i was told that my account was still in arrears and now they not only wanted arrears paid but the full acc, so paid the whole account instore, when i tried to use the acc again i was told that i have 0 credit available, to my knowledge this acc was settled not only the arrears but whole acc that i still had time to pay off which i did not, so ihave tried buying a car last month & lost a deal on selling my car because i am still today listed a default, when i contacted rcs & explained i was told that i would get a settlement letter showing the acc was paid up. Nothing came, I lost deal on car. This month I have tried to buy a property and was told that i have a default still, i contacted Rcs over last few days & asked for my statement & was sent a Makro statement