my story with BoA I had 2 CC with BoA $14k and $10k settled both for 30% here is how it worked in my case, they asked my for 1 small payment for each card and remaining amounts in loop sum next month, they said I will get it in writing once first payment are made since these were relatively small payments comapring to total owend I had no problem especially because I open new checking account with another Bank at the very begining of my settlement process and used old account only for settlemeny payment hasn't been keeing any money so there was nothing they could take without my knowladge, I was depositing only what I agreed to pay.
After 2 initial small payment but before next larger loop sum payments I called BoA and asked them to fax my over settlement agreements in writing they did. Also few days latter I received another letter for each account basicaly saying same thing so it works pretty well for me