OP
Go to
https://www.elliott.org/
It is a consumer advocacy site. They tell you how to write letter- go up the corporate chain. Meaning don’t write to every executive at once. They have emails for all corporate contacts. Tell you to start at lowest level, wait a week, go to next level. Do everything in writing be concise and no-threatening in email. Do not add details not relevant- do not be emotional
Tell resolution you want but be reasonable
Don’t demand all your money back for example
Just a thought