[mothered]

We confirmed the item from order # XXXXXXXXXXXXXXXX  was in the box at the time it left our fulfillment center.

So what?

It doesn't confirm that "you" received It.

The only other problem I have had on this account with returns was when I sent back some RAM for a refund about 6 months ago and the item was legitimately stolen in transit.

In that case, It does not correlate with their findings as per below.

there have been repeated problems with returns on your account.

To appeal this decision, please reply to this email to reach an account specialist.”

^ Do exactly that, by bringing your above-mentioned account history to their attention.