Last week I visited Morocco and I bought a phone there because I wanted to use Arabic on it since I'm learning it. It's Nokia C2-03. It was V3.48 and it had (English, Arabic, Urdu, French, Spanish, Turkish, Portuguese, Russian )
Today I updated the software (using Nokia Suite) to the latest version which is V7.63 and the language pack changed to (English, Chinese, Hindi, Filipino, Tamil, Bengali)
Why is that? o.O
You bought what is commonly called a grey import as opposed to an official import. Grey imports are phones destined for a country A but privately imported into country B. There individual or dealer then tries to hide this by installing the language pack for country B. All was fine until you updated the firmware which contains the original language park for your phone which is the one for country A.
The seller should have informed you it is a grey import because there are warranty issues as well as the language issues you just encountered. Language packs can only be installed by Nokia Care Points and there is no guarantee they will do it for you. Other option is to return to the seller and ask him to do it since as he did it previously.