Robinhood review: Investment account

I have worked for 2 weeks trying to get access to my Robinhood account. Due to several attempts by someone else who was trying to change the phone number associated with my account, I chose to freeze my account. I need to change the password for my account, but every time I go through the process, I am told an EM is being sent to me - an EM never comes. I managed to get a call back from a rep on 18June and received a case number - (not shown here). The number he called from is [protected]. That's a Google account and the subscriber doesn't answer - I left a recorded message.

The help links are of no use, and numbers I have called for support are just giving a busy signal and then hanging up.