I received a $200 loan from CashStar Group in 2008. I repaid $60 before I had to close my account due to unauthorized withdrawals from company associated with the PDLs I had out. Also, I was over my head in loans and decided to follow the advice here to send the letters and make payment arrangements.
I found the address, but no phone number:
CashStarGroup
Domains by Proxy, Inc. - DomainsByProxy.com
15111 N. Hayden Rd., Ste 160, PMB 353
Scottsdale, Arizona 85260
and I mailed a money order for $140. About 2 weeks later, it was returned (company not at address).