Old hacked emails

Hello,
in January 2012 my gmail account was hacked and all my emails and folders and contact list were deleted. I was able to retrieve my account however very important emails and info were gone, now that I need some documents I can no longer see any email between 1/2012 till 3/2013. Also the hackers changed my reply settings so that all the people'emails who replied to me were going to a different but very similar email account as mine, ans this lasted for 15 months till I found out about it. i tried to contact google but they do not answer the phone, I file a report online but again no body helped. Any thoughts
?