Complex sentence: Apatow took over the writing-though he went uncredited for not fulfilling the WGA screenwriting credit system regarding how much a producer had to work on to be credited as writer as well-and had elements so disturbing that Columbia had many complaints on some scenes.
Split into simpler sentences: Apatow took over the writing, though he went uncredited for not fulfilling the WGA screenwriting credit system regarding how much a producer had to work on to be credited as writer as well. The final script had elements so disturbing that Columbia had many complaints on some scenes.