Fire Boltt - Different model received on replacement

I have ordered Fire-boltt Invincible plus watch but it has sensor related issues . I asked for replacement but on replacement I received the wrong model they gave me metal strap instead of silicon strap. Hence I had to place replacement order again. But still this time , instead of the required model that is invincible plus black , I received another model only. If it's not in stock , why I am getting other things for which I have not asked . I requested them several times on mail and customer support to provide me the exact model that I purchased with the same silicon strap or please refund the whole amount now. It is the third complaint that I am raising . They have very poor service and customer support is also not satisfactory. Now they are saying nothing can be done now.You will have to use that watch only.Please help me.I am frustated now. Doing this from past *-* months.