Sounds like an overzealous parking attendant needed to write some tickets. Go back to the spot, take pictures to show there are no signs or curbs with markings. Then set the case for trial and see if the wannabe cop shows up. If not, you win. By the way, you might to check the Vehicle Code to make sure there are no laws that would prohibit parking there, such as no parking in a loading zone or yellow zone. Not saying that was your case, but check to see if there are any things in the area that might trigger some obscure vehicle code section.
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Your best bet is to take pictures of the area to show there were no signs or warnings. Then either hire a traffic attorney or set it for trial yourself.