Complex sentence: Then, in January of 2004, Haiducii realeased her version, which some feel inferior compared to o-zone's and was copied without permission, so, she was succesfully sued by o-zone for copying the original song without permission.
Split into simpler sentences: Then, in January 2004, Haiducii released her version, which some feel inferior to the original. She was successfully sued by o-zone for copying the original song without permission.