Country is not listed to de-register iMessage.

Thank you for your help and prompt response, long story short, I managed to resolve the issue via my service provider.

Long story:

• Called my service provider more than once to solve the issue but they couldn't, though they claimed to have reset all settings on my cell phone number. They asked to visit a branch.
• Went to the branch to solve the issue but they also couldn't, though they also tried to reset the settings again and also replaced the sim card.
• Issue was solved after speaking to a friend's friend that works for my service provider. They figured out that my sms's are diverted to the number installed on the other phone (not sure why they didn't figure it out the first few times I called and visited them!) Solved by sending divert OFF as text message to 88444.

Thanks again!