Unboxify - Item supplied was secondhand and out of Warranty

I had purchased a Fitbit Versa Special Edition on **-**-**** from Unboxify Immediately upon receipt I had noticed that the unit had actually been imported in **** (i.e * years earlier). This was evident from the fact that the silicon strap broke within * days and the battery never lasted even * day. Upon approaching unboxify, I was told that I was to approach Fitbit USA who would address my warranty issue. They had even assured me of their support by Whatsapp. Upon approaching the Fitbit in USA, I was clearly informed that the unit was not covered under warranty since it had already been registered for a warranty on Oct **th **** and hence the warranty was over. Obviously Unboxify had sold me a secondhand watch claiming that it was new and that it had the manufacturer's warranty. I have records of all the communication with Unboxify and Fitbit in Whatsapp messages and Email. When I produced Fitbit's mail confirming that the unit was out of warranty to Unboxify, they just stopped responding to my Whatsapp messages and there is no other way to connect with them. I am thoroughly disgusted with their irresponsible behavior.