The two should not be confused. They are two different charges. One is a store charge and the other goes directly to the driver.
Delivery charge = They delivered it; doesn't matter about the proximity. They still had to schedule the driver to deliver it. This fee is usually a surcharge from the store and usually is not given to the driver. It is an added cost because it is not something that you would have incurred if you were dining in.
TIPS = Acronym meaning "TO INSURE PROPER SERVICE". TIPS go to the driver/delivery person. If the food was served hot and at the scheduled time, he pretty much fulfilled his job. A tip, on an average, should be around 15%, OR a flat fee of $3.00 for orders less than $20.00. These people, basically, work for TIPS so if the man was terribly rude, he shouldn't get a tip. However, he really won't see the cost of a delivery charge in his paycheck and this may have been his bone of contention, with you, if you unknowingly, didn't tip him when he fulfulled his job.
http://tipthepizzaguy.com/general/amount.htm