I don't know. Reading your initial post you don't say the MS rep accused you of anything. They (your words here) said "perhaps" and then you took that as a great injustice to yourself and felt wronged.
I don't know why Epic was passing you off, but the Microsoft rep(s) you talked to are right. They have NO control over stat resets or anything like that so logically they can't help you. That's not a publisher issue, that's a developer issue. So, if you want to hate on anyone hate on Epic.
So, if you had this same issue with say Sony and Naughty Dog would you then complain that they were doing it because you didn't have a PSN Plus Sub? Seriously that whole "I pay for this..." got old about 3 years ago.
You got your issue fixed. The people at Epic were the ones that should have helped you. That's the bottom line.