It seems to me that whether you have any claims against this person/entity depends upon whether they acted wrongfully. Commercial landlords are given strong rights in Arizona. However, they cannot violate a valid lease without consequence. If you had breached your lease, a landlord or property manager may have the right to lock you out. I would need to have answers to various questions before I could provide you useful information. For example: did you have a written lease? Had you breached the lease in any way? Had you received any prior notice that ownership of the building had been transferred, either through foreclosure or sale? What does your former landlord say about the situation, assuming he will return you call? On what basis were you singled out as the only tenant who could not return?
There are probably other questions which would arise, but this would be a start to determining what your rights are in this situation. I would be happy to discuss this with you if it is too complex to write online.
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It sounds like the one breaking the terms of his lease here is your "landlord," and you are paying the price. Unfortunately, this type of situation is one of the risks you take when you sublet. It happens. It sounds like the other subtenants may have made deals to lease directly from the property owner. Is there some reason the property owner might want to rent to the other four and not to you? After verifying through the assessor's office that the property owner is the property owner, I would try talking to him to find out if you too can rent directly from him.
I'm not sure why you refer to the person who locked you out as a "self-proclaimed" landlord. If that person owns the property, he/she is your landlord. You should be sure your facts are straight as to who this person is and what is their relationship to the property.
It sounds like you are a sub-tenant of a tenant (aka a "sub-lessor") who leased the property from its owner (the true landlord). As such, your tenancy is subject to the terms of the the sub-lessor's lease, no matter what your sub-lease says.
While you may have a claim against someone, that cannot be determined until all the facts are known, including the terms of the sub-lessor's lease and why the lock-out occurred. You may have rights to recover your property from the premises, but you would be well advised to make peace with the property owner, but it sounds like it may be too late. If you relocate, be sure you are leasing directly from the owner of the property, or at least get a copy of the underlying lease and also get the property owner to approve you as a sub-tenant.
You need to speak with a local attorney to go over all the facts and explore your options.
The above "answer" is for discussion purposes only and is neither intended as legal advice nor to create an attorney-client relationship. An attorney-client relationship is not created until after an in person consultation and I agree in writing to provide representation. I am licensed solely in the state of Arizona. You should consult with a knowledgeable attorney in your jurisdiction.