Istanbul to Sofia early June

Hi Everyone, 

We are trying to get from Istanbul to Sofia using the night train, 

We have found it very difficult funding information, the Turkish train company websites shows slightly different information to the Bulgarian website, which is in general much clearer, but the timetable from June to September is missing. 

I am very tired having slept 4 hours the last 2 nights :( so might be missing something obvious. 

Advice on how to find reliable timetable info, and book reservations (any way to book remotely via phone or email?  would be great!)

Many thanks