How to enable other languages for MailChimp List Subscribe Plugin?

I have translated the MailChimp provided MailChimp List Subscribe Form plugin for wordpress.

I used poEdit to edit. At wp-config.php I have language set as ar_SA. Which works for the themes I have used in two Bilingual sites. But the mo file had to be renamed to ar.mo

I got two problems:

1. While updating the catalog poEdit crashes. But I could save the .po
   and generated .mo successfully.

2. The translated .mo doesn’t appear for the confirmation success or error messages through the Ajax calls which its supposed to.

I am submitting my .po file link here for experts to view. I have saved the settings for translation in the files.

Translated Bangla.po file || Translated Arabic.po file