Towing: Vehicle Towed from a Store Parking Lot While its Owners Patronized a Second Business

My question involves a consumer law issue in the State of: California. I pulled into a shopping strip and parked in parking designated for the liquor store i intended on making a purchase from. My boyfriend walked in, then i called him back n told him lets eat at a restraunt 2 doors down, same building before we made our purchase. We were inside approx 35 minutes. When we came out we returned to the liquor store. As my boyfriend was at the counter to make the purchase i realized where i parked my car was empty when i walked past. We both went outside and looked and sure enough it was gone. We returned into the store where the clerk told us she had my car towed because there were signs posted. We returned outside and the sign read: "marina liquor parking only or be towed" there was no signs as to who towed it or a phone number. After returning into the store and confronting the clerk she wrote down the company and phone number that towed my car. Is this an illegal tow? We parked there to purchase from that store. The tow truck company did over $500 in damages on my vehicle and lied saying the owner called and police verified my plates were stolen so they made the tow. My plates were not stolen, and I've contacted the county police and they verified my plates were not run by them.

Towing: Vehicle Towed from a Store Parking Lot While its Owners Patronized a Second Business