I spoke to live chat and they said that I should be able to list 100 a month irrespective of how many I have currently listed.  So technically I should be able to list a further 100 today.

However since I only upgraded to 100 yesterday then I have to sit on that for a month

Who knows!!!!!! 

Live Chat aren't always helpful or right. If you click on Customer Support in the top right corner and follow the links you should be able to find ebay's phone number.

Ok thanks I will ring them instead