apt complex towed my car, towing company sold it without my knowledge

I was on a vacation for 1 & 1/2 month during which my apt complex(park plaza apartment, Mountain View) told a towing company(Auto Ambulance) to tow my car parked in valid parking lot of my apt complex (for expired registration, I had not pasted the new registration sticker I got from DMV). I had the parking permit to park my car at the place from where it was towed. I was paying the rent for all time during my vacation to the apt complex.

The towing company had written me letter to claim the car but I was on vacation and was not looking at my mails. The towing company auctioned my car on 9th Jun.

I came back from vacation on 9th June night and could not see my car in parking lot. I got the towing agency's number from apt complex manager and called to check on them, they told me that they had sold/auctioned the car and I cannot do anything on this anymore.

I am looking for legal help on this matter. Write me at vaibhav.chopda [at] gmail.com if you think I can do something legally on this matter.