[Shade7]

Last response from them was the chat said that someone will contact me, and that my case was being reviewed. It was escalated because I was not given a reply in a week.

Given they didn't discuss anything about your claim, It's Impossible to determine the Intention of the phone call.

Please reply after you've spoken with the presidential liaison representative.

This is what I got from their email:

Due to the unit being deposed of and our company not being able to diagnosis and inspect what the problem could have been for repair we are not able to exchange or refund the unit without it physically or without the model/serial# tag from the unit. What I can do for you is offer you a rebate @ 20% toward a new monitor not to exceed $500.

What should I reply with to persuade her?
The last part of "without the model/serial # tag from the unit" is confusing me because I sent POP along with a picture of the information of the monitor and it clearly shows the S/N.

Since they are offering “20% off a new monitor up to £500”, they have in my opinion accepted responsibility/liability. Based on this I would still pursue a full refund/replacement. Ask to escalate and formally complain. I would keep mentioning that you have already provided SN and POP. Keep pushing them and I believe you will get your desired result.