Complex sentence: São Paulo continued to claim that Oscar belonged to them and lodged legal appeals which would prevent Oscar from playing for Inter in vital Copa Libertadores fixtures before a settlement was agreed upon between São Paulo and Internacional on 30 May 2012.
Split into simpler sentences: São Paulo continued to claim that Oscar belonged to them and lodged legal appeals which prevented Oscar from playing for Inter in vital Copa Libertadores fixtures. Eventually, a settlement was agreed upon between São Paulo and Internacional on 30 May 2012.