FILA DISRUPTOR II product complaint

I purchased a pair of Women's FILA DISRUPTOR II BLACK Shoes during 2019, specifically because they had thicker soles than most other brands of sneakers and my other sneakers' soles had worn out. In this instance, I have no problem with the soles, however it seems that the uppers are problematic. They were certainly not a cheap pair of sneakers and I had expected to get many more years of mileage out of them. After some 3 years, I note that the upper material is tearing away from the soles of both the left and right sneakers. Whilst I understand the concept of fair wear and tear, and I also understand that the product carries a year warranty, I would not have expected this to occur (particularly in view of the expense, and as the sneakers are not even worn on a daily basis) and accordingly I am more than a little disappointed in the brand! I accordingly addressed my complaint via the social media channel on 24 November, as well as per e-mail to ***, to which I have received no acknowledgement of receipt. I am reluctant to purchase a new pair of replacement sneakers in the circumstances where I am extremely unhappy.