Assurant Damaged Device Returned - Not Recived

My Daughters Phone was STOLEN and after filing a CLAIM on line ASSURANT Denied my CLAIM. After trying several times to get a Reason why they Said the GB was incorrect. I have BEEN paying for INSURANCE for my 4 phones for past 15 years and NEVER FILED a CLAIM. I had a T mobile REP stay on the phone and explain to the ASSURANT REP the phone type, color and GB on file. After 1hr and 15 min the rep left me with the ASSURANT REP. Two days Later my CLAIM was AGAIN DENIED> I have Been with T MOBILE for 19 years and they ALWAYS have had GREAT CUSTOMER SERVICE> If i had known that the INSURANCE was Thru a 3rd PARTY I WOULD NEVER PAID FOR THE INSURANCE for all my PHONES> I have SINCE CANCELLED MY INSURANCE ON ALL MY DEVICES…. T MOBILE PLEASE DO AWAY WITH THE ASSURANT COMPANY. THEY REALLY ARE NOT HELPING ANY ONE OUT HERE BUT THEMSELVES> I have to BUY A NEW PHONE thru T MOBILE because the LACK of CUSTOMER SERVICE ASSURANT has towards people that need their HELP after paying $$$ for YEARS!  I am VERY UPSET and NOT a HAPPY CAMPER>