First National Bank of Marin Turned over to several collection agencies. California

I opened a credit card account with First Bank of Marin in 2003.  The limit on the credit card was $300.00. I lost my job and could not pay the balance.  Several years later a collection agency out of Texas contacted me and offered me a selttlement to pay the debt for $555.45. I sent them a money order for that amount and I received a letter that the account was paid in full in June 2015.  Right after I paid the account off, another collection agency contacted me and told me I should have not paid the previouw collection agency for the debt with First National Bank of Marin and that I should pay them.

I emailed the last collection agency the letter I recieved from the first collection agency.  They still contended that the first collection agency was bogus.  Sine then I moved and antoher collection agency representing First National Bank of Marin has contacted me and they said I still owe the money and that I need to show proof I paid the other collection agency.  I no longer have the letter because of the move.  I think I will hire a lawyer to resovle this.