stuff in godown gone does this comes in theft

we hav no rent receipt no rent agreement./ had godown 4 last 30yrs /property belongs to mandir trust /will court by this if i said rent agreement (non registered) got destroyed in flood. i have complained 4illegal construction over ten times to police n mcd since july2014 n mentioned that we r legaly in possession of this godown.in person n thru email. / hydro bill and complaints to mcd police is it gud enough to put up a case in court. we had stuf worth 3lac that is gone...so can we put theft case./ Y court does not consider email as legal notice ...? thankx