Ditto. In many states you have a number of days to take a car back and get your money back no questions asked. Check your states laws or look at the contract you signed.
Open the fuse box next to the battery and pull the IOD/Memory fuse for 2-3 minutes. This will reset the Body Control Module (BCM). The BCM controls most of the electronics in the van including the chimes. Could be as easy a fix as that but, not likely.
Good chance your dead battery is being caused by what is called a "parasitic draw" meaning something is drawing current when it shouldn't. This can be a costly and time consuming problem to fix. Erratic interior lights/power windows/door locks can be clues to the source. If you wind up keeping this van come on back.