Product not working as advertised on the box and quality

We bought an Volkano Serene Series in Febr 2021 ( Vk 5073) in December 2021 it started giving problems didn't charged ,after I bettled with the watch I took back before the warranty. The shop did give me the Volkano 5072.now the problems is keep on losing connection. The functions on the watch has to be reset all the time .why buy the product if it is not working properly.