Login troubleshooting

Payflex customer services is non existent. I've been trying to change my cellphone number but I can't log in to my Payflex account because I've lost my registered cellphone number and they dont give the option to login with you email by sending OTP to your email address it's so stupid to only have the cellphone number option for otps. Its been a week maybe more that I've been trying to change my cellphone number omw.