I need help with an eBay haggler might you have some advice?

I have some records for sale. I never listed any “combined shipping” option. Some guy is following all my listings and has won two.

1. He first won an auction
2. He asked if there was combined shipping
3. I told him no I have not listed combine shipping
4. He wins a second auction
5. He is now questioning why I don’t do combine shipping

How should I respond to this user? Can I block him from further bidding? He’s acting very entitled to something to an option I never listed plus he is being unreasonable as if I’m some power house seller, and he is not even guaranteed to win any auction.

Am I being the unreasonable one? These are rare records and bidding started at .99$ and he has won them from beyond dirt cheap! 5$ a piece and typically they would sell from 25–35$.

What should I do?