Registered Vehicle in ex-friend storeage Unit

I have a legal registered vehicle and some other belongings in a ex-friend storeage unit. I'm not on the lease, but the ex-friend has given me authorization to enter. ( secret codes and combo for lock) I would like to know what are my rights in order to get my stuff out? Is their a legal form or complaint that I can file in order to get my vehicle and stuff. He has not pay the storeage unit, but I'm willing to pay it just to get my stuff. Also, I'm unable to contact this person, he has no phone number. When I went down to the Manager's office at the storeage unit, they informed me that I would not be able to enter since it is private property and since I'm not on the lease.
Please help me, I want to get my stuff out so the fee's do not go up any more. Is their any forms that I can file in Court? What are my rights?

Thanks again, anyone please help!