unable to change default email as business no longer uses The Box

I originally had a personal Box account and then intergrated it with my previous employer business account and now I have left the business and trying to get the default email changed back to my personal email address. How can I do this? I sent email to my previous employee who informed me to reach out to The Box. Can Anyone assist? Thanking you in anticipation. Ps I don’t have access to previous email so please email to <personal information removed>