Tell the landlord nicely that what he/she is doing is both against the Torah and Halacha and ask him/her where they would feel settling this matter.
Our friends recently fixed over their basement as a rental, their neighbors who are big Rebbes build a fence to block the entrance so that the tenants cannot bring in furniture. His calls are not being returned.
As a suggestion, perhaps try calling 1 845 HALACHA where there are qualified dayanim from a top Beis Din on call day and night except for Shabbos and Yomim Tovim.