If you're not sure whether you can use a company's name as a synecdoche for an account you have with that company, substitute in "Bank of America" and see if it still makes sense.
Help, someone hacked into my Facebook!
Help, someone hacked into my Bank of America! ✘
All my friends have Tumblrs.
All my friends have Banks of America [or Bank of Americas]. ✘
My mom still doesn't have a Twitter.
My mom still doesn't have a Bank of America. ✘