[fishly]

We have stopped refunding amz completely after that  as we used FTID multiple times in the past like maybe 2-3 times each (way before we knew about how risky it was)

Your SEing was obviously excessive, hence suspicion was raised with Amazon.

The tracking was shown as delivered - thats how we got the refunds, by contacting support after it was delivered and they manually refunded. 

I wasn't aware of that - they didn't clearly Indicate that you've been refunded.

Going by their message below, they've stated you've "requested" refunds and not received.

Your correspondence with us shows you have requested multiple refunds.

We sent back empty packages with modified return/sender address but I guess they might've reprinted the labels

A lot of carriers tend to reprint labels, DHL being one of many.

This was the only thing at the bottom after listing the items that weren't returned:
"We want to do what we can to ensure that you are happy with your Amazon shopping experience. If you have any questions regarding this email, please reply to this email."

You've killed the account with the flawed so-called FTID.

I wouldn't bother contacting them.

We waited like 3 months and 5+ legit purchases inbetween each FTID but yeah, we did go overboard using the same method. That's why since then we haven't been refunding and only using it for legit purchases. The carrier was my local one, not DHL and we dropped it off in the street post boxes. We did get our refunds for the TFID and my friend got that email like 3months after the refund.

I just hope that this is a warning message and not a message of them rebilling