Here's a friendly reminder to always count how much money they pay you before walking away. This pizza delivery driver learned that the hard way when after parting ways with a customer at a gas station, he realized the customer was $7 under and it was definitely not an accident. Thankfully, he had this dude's number. Of course, the guy did not pick up his phone, which totally confirms that he shortchanged the delivery driver on purpose. The best part about this driver, though, was his relentles…