Like losing existing files, or I lose any other features?

Thanks for your information

If you are looking for an auto call recording option, go for the international version only

If I change CSC, are there any demerits?

Hi I have visited the samsung service center, they confirmed the device is tried to install unauthorised software. Same I have complained to the Noon customer service which I bought the device then it returned and they rectified the issue and refunde...