Capital Billing Services Collection Agency Los Angeles California

I received a letter from Capital Billing Services saying they were representing Readers Clearinghouse in a debt owed since 2012 in the amount of $878.90.  and were going to report to credit bureas if not paid. I never heard of or ordered books from this company. I was told they would settle for $600 to close account. Capital billing had no complaints on BBB so I though maybe it's real to them but a fraud by Readers Clearinghouse, so I foolishly paid $600 not to spoil my credit rating. I researched readers and called back collections ,argued with them, Saying I was going to get a lawyer and sue book company they reresented for fraud. they put me on hold and said they will try to help. call tomorrow they said... I called CC company and money was refunded already ,so I closed card. Research found- Caution on Readers Clearing house- address found- *** ******* ******, *** ****,** *****- * ** unit apartment building, companies name is under Phillip Roberts 877-9772876 , www.readersclearinghouse.com web page is now offline.