I had a DropBox account that had been idle for awhile, when I received a notice that the email had been changed without my knowledge. I think the account was empty or with little value but I thought I should go recover the account to make sure.
DropBox support was horrendous, first robo-sending the same "check our FAQ" response for a week, then sending multiple "we'll have someone look into this" for another few days.
Bottom line is that I never was able to get back into the account and was never able to communicate with anyone.
I finally gave up because I'm pretty sure the account had nothing of value in it and after two weeks it was probably moot anyway.