useless insuranc

My tab 4 got ****** last at my work, in my office, under my table in my handbag, have insurance at mtn, 24 hour mobile, for 6 years, and its the first time I claim. the insurance said that my claim was not sucsesful, it must have been in a locker..... if my tab was in a locker, how will I hear my phone ring. its been almost 2 weeks and NO response for Mtn. Could you please help!!!