Small Claims and Internet Purchases

California Internet Purchase. I purchased a water pump from a company in San Luis Obispo CA. I ordered the item over the phone, and gave credit card info over the phone to the salesman. The pump arrived broken. I returned it, but only received a partial refund. I live in San Diego CA.
Who has jurisdiction over this claim... San Diego or San Luis Obispo?

many small claims courts will make you sue where the defendant is in that situation but since it all occurred on the web there is good reasoning that your location is also where the transaction occurred and you should be able to sue there---courts come down differently on this these days but many say sue where the defendant is located.