We paid $50 for the ad on May 10, Transaction ID: 53D58052X8451781L. The funds are not reflecting in the Ad account.
Found the transaction in PayPal, although it was under a different transaction ID. Also haven't figured out why it wasn't credited. I have a ticket open with PayPal to see if we can track it down (the best I can tell is simply PayPal didn't notify the server of the payment). Either way, I've manually adjusted your credit (the payment doesn't show on your account at this point because still trying to figure out what's going on and seeing if it will show up later), but you do have a credit for the amount on your advertising account.