Lastly, if nothing else has worked, it's time to try the most drastic step of all: deleting everything from your iPhone and setting it up from scratch.
N'ikpeazụ, ọ bụrụ na ọ nweghị ihe ọzọ rụpụtara, ọ bụ oge iji gbalịsie ike ime ihe niile: ihichapụ ihe niile site na iPhone gị ma mee ka ọ ghara ịcha.