Incrasebux payment mistake

Before anything else, I am so thankful to the admin of incrasebux for my 3rd payment I already received.. That was requested on Dec. 20, 2008.

But I think there's a quiete mistake about my payment.
I had requested the amount of $13.37 on Dec. 20, 2008.
Last night, as I recorded my current balance, I had $5.58..

But today, I only received $6.98 on alertpay(Jan. 27, 2009).
And my current balance now is $12.085.
How was my payment made?
Why it was deducted and turned it back to my current balance..?
I've sent a ticket on their support system and will wait for any clarifications they had..