Fire Boltt - Misplaced the watch sent for repair

I got an invincible plus Black stainless steel strap watch a year back from Fireboltt. The display was not working now, i raised a complaint with Fireboltt. Their representative assisted me to send the watch through the courier booked by them. I thought they are asking the watch for repairing it and sending it back. After a week, fireboltt sent me a replacement watch. This is completely a different watch with a rubber strap. When i purchased my watch a year back, the black stainless steel strap costed Rs.**** whereas rubber strap watches are Rs. ****. I raised a complaint again with them stating the replacement watch is of different type. Their customer representative asked to keep the watch which is sent. They are even normalizing the fact that such kind of errors will happen and we have to live with it. I even requested them to send my original (black stainless steel) watch back because i got it gifted from my fiance which has more sentimental value. But they are not responding at all for my complaints.