I got a letter through U.S. mail from First National Collection Bureau , Inc ( 1st letter i 've rec 'd ) stating i have a {$11000.00} debt. They are offering a XXXX % discount on that debt if i make XXXX payments of {$180.00} w/each payment within 30 days of the previous payment. They threaten that unless i notify them within 30 days of receiving the letter that i dispute the validity of the debt then they will " assume '' the debt is valid. 
