I had a similar outcome with my Versicharge, 6-50 outlet, and 8-2 wire. It was a cheap Leviton outlet. However, I was not aware of the necessity of an industrial grade outlet in this application, so I just cut back the damaged wire and installed another Leviton. After a couple of years, when I learned about the outlet issue, I checked the outlet and noticed heat damage. I replaced it with an Eaton industrial outlet and have not had any issues over the last year.
Something to consider is that your charger pigtail will need to be replaced because of the damaged plug. I was fortunate to find one on ebay for a reasonable price. At this point, my recommendation would be to hardwire the charger.
I had a similar outcome with my Versicharge, 6-50 outlet, and 8-2 wire. It was a cheap Leviton outlet. However, I was not aware of the necessity of an industrial grade outlet in this application, so I just cut back the damaged wire and installed another Leviton. After a couple of years, when I learned about the outlet issue, I checked the outlet and noticed heat damage. I replaced it with an Eaton industrial outlet and have not had any issues over the last year.
Something to consider is that your charger pigtail will need to be replaced because of the damaged plug. I was fortunate to find one on ebay for a reasonable price. At this point, my recommendation would be to hardwire the charger.