Cruel and dishonest Nimble

These people sent me a settlement letter and i settle, then they sent me an email saying i still owe some money, of which i didnt understand and i still dont. A few days i go i called them and the gentleman i talked to said to me he can see that the bill is settled. I asked for a settlement letter , still nothing came through. Funny their name is still on my dashboard, as if i owe them anything.