Answer 1

You might be better emailing [e-mail]

Answer 2

From the app, left upper corner, in any section of 3 lines options, you can see "sololearn pro".tap on it and see price.
Or any pro tagged content, tap on it, you can see deatails about prices..

Answer 3

When did you send an email to them? They will respond, you have to give them time - imagine how many emails they receive from people all over the world.
Why don't you use a currency converter online?
It may be that they don't offer it in other currencies to avoid losing out on conversion, many companies only stick to the "hard currencies" for this reason.