Slope Parking

In short, I had an experience here that was, best case scenario, super shady and, worst case, straight up theft. As a result, I won’t be going back.
I had a ZipCar reservation until 8:00 PM. I finished up early and took the car to the garage at 7:30 PM. My place is right around the corner and, upon getting home, I realized that I left my phone in the car. About 10 minutes had elapsed from the time I dropped off the car to the point that I returned to the garage. The ZipCar was nowhere to be found and the attendant kept saying, «I don’t know, I saw someone take the car out after you dropped it off.»
OK, if you know about ZipCar, you know that it is not possible that someone took the car out as I still had it reserved at that time (it was around 7:45 and my reservation ran until 8:00). The only other card that could unlock the doors and activate the car is the card used by the garage attendants to park it. I verified this with a call to ZipCar who confirmed that a) they do not overlap reservations and b) there were no reservations after mine for that car. I walked home and returned two more times that evening and each time the same attendant gave me the same story, «No, I just saw someone take the car out after you.»
I won’t say that this was outright theft here because I have no definitive proof of that. But, this is super shady at best. As far as I can tell, there are only two realistic options here, neither of which reflects well upon this place: 1) the attendant used the garage card to allow someone to drive the car under my reservation or 2) the attendant found my phone, took it, then «hid» the car (they have an upstairs area that is inaccessible to the public) to make it look like someone else took it out in order to cover himself.
Just be wary of this place and make sure that if you do business here you clear your car of any valuables. I take full responsibility for the stupidity of leaving my phone in a ZipCar, but this experience was shady enough that I’m never going back to do any business here.