I received the receipts saying that the letters were received by both parties, the CEO and the collections, I called them and used their voice system. It says the money is still owed, but I don't know if that really matters in this case.
Anyway, I'm going to send out the next letter, #2. I'm not sure what date to send it on. I sent the 1st one on May 15, 2012, so do I send #2 on May 25 or 10 days from the date they received it? However, I don't know the exact date they received it on, since I can't make out the scribbled name or date on the receipt. I received their acknowledgement on May 21, 2012, so do I sent #2 on May 31 which is 10 days from when I received the receipt? Also, do weekend days count in this?