OC response to settlement ltr

This is a strange one. I have a corp. AMEX "Collection" account on my credit reports since last May. Before the account was placed on my reports, I sent a validation letter to the CA. They did not validate. The CA ceased all contact but all of a sudden the acct was reported 5/02. Depending on what day you call AMEX, they will either not discuss the account or state that they in fact did not report the account, the CA did so. However, the reporting detail shows AMEX's Ft. Lauderdale address as the source. This account became past due only due to my employer not paying several expenses. Last week I sent AMEX a ltr. from my employer stating this fact and requesting AMEX remove the item from my reports upon receipt of my final balance payment of $1500. AMEX received the letter on yesterday and today I received an email notice from Credit monitoring service that shows "AMEX reported a collection". When I look at the reporting detail it is exactly the same. So how could they "re-report" something that they have always reported? Could the CA have actually reported the collection under AMEX's name? Anyway, I am awaiting to hear AMEX's response. This is the only item on my credit reports so I'm battling to have this item removed. Because of how AMEX (or whomever) reports, this is effecting my FICO 40 to 80 points! On previous calls, AMEX has stated that the only way they would delete would be to receive a letter from my employer. Until now, I was unable to get such a letter. I was finally able to pinpoint the charges that were never reimbursed and my employer agreed to write it. BTW, my compnay's AMEX account is set up to have the employee assume full responsibility for payment. But of course it also states that the company must reimburse all applicable charges. Another recent irony is that my employer's program administrator sent the letter to her AMEX contact and he called her back and said that AMEX did not report the account, the CA did. He said that "we" would have to take it up with the CA. Any thoughts on this one???