Poor service and comm

I am receiving a very bad service from Fitbit;I have bought Fit bit HR last year July 2018 ;It has been giving problems;I have taken it back for several times to where I bought it way before 1 warranty expiring.I was advised to restart it for several times ;it's now dead. I have been engaging with with Fit bit support ;different agents responding with different responses. .The service I am getting is extremely poor.