Is it permissible for a new Muslim to keep their foreign name that means "Allah" or "God" in Arabic, and what is the legal ruling for that if they refuse to change it? And what is the ruling on being named with the names "Al-Ilah" and "Ar-Rabb"?

It is not permissible to be named with the names exclusive to Allah, such as: Allah, Al-ilah (The God), and Ar-Rahman (The Most Merciful). Whoever was named with them must change them. And whoever does not change his name after knowing the prohibition is sinful. There is no blame in informing about him by his forbidden name.