Registration deadline

Please i have two different deadlines on my admission notice and jw201.The former bares 4th september and the latter bares 30th september.Which one does the embassy base on to deny visa if deadline date is up or almost up? I wrote to the school for extension letter but they told me not to worry and they have extended my registration deadline.My problem now is with the embassy.If they use the deadline which is 4th september,then it is likely they may refuse me considering i have barely 2 weeks left.The embassy too is crowded with applicants so there is no guarantee i can do my submission nd interview any soon.