I realize that on the face of things, this all seems unfair. However, the terms of your lease will prevail; it is a binding contract. The fact is that many times a lessor retains the right to make certain changes to such an agreement (provided that they are not changes to the material terms). That having been said, they also typically have the responsibility to notify the their lessee of changes. Again, you will need to look at your lease agreement carefully. If things are not clear or you feel that the lessee has violated the terms of your lease, you can consult with an attorney. For the prce of an hour or so of their time they can review the document and give you guidance on how best to proeceed in this matter.