Hacked account and changed information, please help!

My mother's email (removed for privacy) account has recently been hacked. She received an e-mail confirming a change in her email address (from *** to g.n.hunal), which at first she thought was harmless. However, since then we are unable to log into her email account, and all the security information has been changed. Despite this we have tried to fill out a form, using my email address as a Contact address, however the information provided was insufficient. On top of this, we attempted to send a code to her mobile, only to discover the mobile number has also been changed by the hacker. For some reason, my mother is still receiving emails to her Blackberry mobile, and when we requested a reset link, the email appeared on her phone, but in a different language. The emails on the account are highly important, and it is imperative that the account is either recovered or deleted completely.