You don't have a case against landlord

Freedom of Contract, guaranteed by the constitution.  As long as the new lease is not violating any terms of your current lease, you do not have a case.  

In addition, where is your damage so far?  You cannot sue someone without injury.  

If you had a case, it is the case against your partner, violating certain partnership agreement, if you ever had one.

If you don't have any agreement with your partner, consider this a lesson and be careful who you work with next time.