To me it looks like mould (powdery mildew) caused by excess humidity and poor air circulation, something neem can not fix, besides, neem should not be used on flowers. In fact, in my country, it is ILLEGAL to use NEEM on ANYTHING intended for HUMAN consumption. If you had done something before it got this bad, a possible cure strategy may have rescued your plant. Now that it has become this advanced, there is probably nothing that can be done to rescue her, unfortunately. Sorry, don't know what else to say. ..... Organoman.