Hello, at the end of May 2016, my friend concluded a lease agreement for a housing unit for an indefinite period, which was not completed at all, eg there was no kitchen, which was delivered only in December 2016. The ORAL agreement on non-payment of rent the apartment will be suitable for living. The rent has been paid since October 2016 and since November I have taken over the lease agreement. We have now terminated the lease of the apartment at the end of March 2017. After that, the owner started to cause us problems with the bail. It is said that we are not entitled to a deposit that we are not paying rent at the beginning, that the deposit is forfeited. After looking into the real estate cadastre, I found out that the apartment was not approved as an apartment until December 2016. Is it possible to consider the lease invalid or to take it as a "deception" of the tenant? In addition, no one warned us all the time about not paying the rent (because we agreed otherwise, but not in writing: /) and only after the request for termination of the rent they pulled it out on us. Thank you very much for the information.