That does seem strange and at the end of the week and end of the day maybe there just was not enough open interests to close their positions to fill your order. Looks like you could have bought a half a mill in the morning under .007........the close was .0075 with a 3000 share trade... 500 thousand would have been over 10% of the days volume.
Makes me think the price is going up Monday and you got shut out at the window. (ever play the horses?)
I would also like to know what others think on this.