Just got this letter from Kroger. Need help.

So I just received a letter from Kroger stating 3 years ago I was over paid $600. Now I have never realized or noticed this also I haven’t worked for Kroger since 2022. Can someone please enlighten me on what I need to do and if I actually have to pay back a company I haven’t worked for in years???

So I just received a letter from Kroger stating 3 years ago I was over paid $600. Now I have never realized or noticed this also I haven’t worked for Kroger since 2022. Can someone please enlighten me on what I need to do and if I actually have to pay back a company I haven’t worked for in years???