Hello friend ,the reason people want 50 tech is because that is the limit. That is ONE SLOT.
Nations do not want to use their foreign aid slots , unless it is for the utmost importance.
I would give you aid if there were unlimited slots , but because that is not the case , I must keep my precious slots open.
I have pending deals and therefor can not assist you , although I wish you all the best , and Happy Holidays.