Look up "works for hire" doctrine for copyrights.
First off, oral contracts are just as enforceable as written contracts (unless the Statute of Frauds applies, such as real estate contracts, services > 1 year, and sale of goods > $500).
Second, it's likely that the photos that you shot for the shop owner may be considered a "work for hire", meaning that the shop owner (and not you) owns the copyrights. Meaning the shop owner can do whatever he wants with the photos.
Next time, put a written contract together stating that you retain ownership (and all copyrights and other intellectual property) and all other rights in your photos, and that your photos are NOT "works for hire". You might want to put the relevant details of your engagement as well (such as compensation, length of service, what non-exclusive rights the owner has in the use of your photos, etc.).