He did what's best for his "customer" which is to offer a refund for the return of the snake a FULL refund. I don't understand why this is confusing you, or why if customer service is your big issue that you wont take him up on it.
TBH in the time frame that you've had the snake, and the "petshop" (I use that lightly since it's apparent the place in question is anything but, (that being better than a mere petshop)) origin of the snake in question I would be happy that they are offering to take the snake back at all since most places (even the most well meaning and well run) have a no guarantee on live animals once you buy it, or a very limited guarantee.

just baffled is all
also, just my .02$ for being a WC it looks pretty spiffy