It would help to know what country you're in...!

If in the UK I'd recommend Hiscox... but I do believe they export as well.

I bought my first Hiscox case after their rep walked into a music shop that I just happened to be in, buying my Yamaha FG260 12-string. They had only recently started up in business at the time and were looking for sales.

Anyway. he was carrying a sample case. He opened it to reveal a Gibson acoustic (can't remember the model, it was over forty years ago!), closed it again, laid it down on the floor and proceeded to jump on the case quite vigorously! Then he opened it again to reveal a completely undamaged instrument.

Needless to say, I ordered a case for my new 12-string there and then - and I'm still using both the guitar and the case to this day.

Anyway, their range is pretty extensive these days, and they produced branded cases for many of the 'big name' manufacturers (including Yamaha, Lowden and Burns)... whilst a case for a balalaika isn't listed on the website, I believe they can produce cases for pretty much anything!