To convert EDB to PST format, I can recommend here ExMerge.exe tool. It's a freeware utility provided by Microsoft to extract emails from EDB files (normal as well as corrupted) and save them to new PST files. If you're not familiar with ExMerge.exe and how to use it, you can read this blog post: wordpress.semnaitik.com/2014/04/28/convert-exchange-edb-to-pst-format/

You must read this blog post before you can purchase any 3rd party paid software. I hope this blog post would be helpful.

Thanks and best regards.