3rd party account won't verify account owner

Legacy 3rd party employee discount account, began with sprint. I've called several times and gone into stores and nobody can give me admin access to my account. I need to update my information but I have to call or go in and jump through hoops in order to get anything done since it won't verify my account. I've tried pin and social security number verification. I can't access my own account at work for security purposes.