Russian letters in feedback form not working

Hi

When someone writes something in russian letters in our feedback form, it comes through like this:

?????????? ???????? ??? ?????????? ??????? (???? ?????????) ? ???????????? ??????? (?? ????????) ???????? ?????. ???????? ?????? ?????. ?????? ???????? ?????: ?????? 2 ? ?????? 3,23 ?. ?????????? ???????: ????? 72 ?? ??????? ??????? 6 ?? ??????? ????????? 5 ?? ?? 10 ?? 16 ???????. ????? ???????? ????????? ????????? ? ????? ?? ??????, ? ????? ?????.

How can I enable support for russian alphabet?

Г, Д, ё, Ж, П, Ф, И, й, Л, Ц, Ш, Щ, Э, Ю, Я

etc.