They say that your payments is not accepted and demand more. It is acceptable, but by doing you so you have bound yourself and admitted the debt is yours.
They will cash your check, have no fear of that. Just keep on doing what you ar doing and eventually you will have paid off the debt. Just keep close accounting and documentation.
The best way is to see if you can a lump sum settlement with them. You could probably get 30-40 cents on the dollar by doing this and just get this monkey off your back…now.
If you just continue sending payments it will be until hell freezes over when you finally pay off the debt. Better to cut your loses and start afresh.
Dave Ramsey’s method is good, as one poster mentioned, but it sounds like you don’t have the extra income to afford this type of program. However, if you could swing it then it might be beneficial for you to do so.