I know that there is an ayat in the Qur'an that says that Allah SWT does not cause one ayat to be forgotten or to disappear/be changed without substituting one that is better.
Since the Noble Qur'an was revealed in the period of over 20 years, I can understand why Allah SWT would cause certain ayat to abrogate other ones--the times change.
What I do not understand is how can a hadith abrogate Qur'anic ayat as some Muslims claim?!?
Since Allah SWT states in the Qur'an, that the Qur'an is clear and detailed, that nothing was left out of it that we should know about, then how could hadiths (Prophet's pbuh sayings) abrogate Qur'an? Wasn't Prophet pbuh supposed to abide by and deliver only the Qur'an?
Didn't Prophet pbuh also forbid writing anything else from him but the Qur'an?