Problem with Central Portfolio Control

Our debt from WAMA has been sold to CPC after 7-8 months of no payment. They are now contanstantly calling my husband at his work phone number and work cell phone numer to settle this account at 50%. He has told them not to call these numbers but, they keeps calling. They do have our home phone number and they have sent us a letter about a week ago. We do not have the 4500.00 to settle this account at this time. Can I file a complaint because they keep harrassing my husband at work? Also when they say you have 30 days to dispute the dept, is that a straight 30 days? or 30 working days? I plan on sending a DV letter as it gets closer to the 30 days of the letter.

Any one have any input on what I can expect to settle this for?

Thanks for your help