Wall or tower is longer than permitted
I was placing 7 of these Towers from the Construction Defence interface and i managed to place 7 and then the error message came up that said 'Wall or tower is longer than permitted' and it deleted 6 of the towers. However it appears to have also charged me the diamonds for the 6.
Maybe i am just being a scrooge :) but I see short in diamonds the same amount it would charge for the 6 at the discount of 25 %