[i need a motherboard and pci express cable replacement, where i can buy?]

well, i have my case open, and my  cats just bitte some part of the cable of the pci express, i now use 2 of them because they make the extension broken, and bitte a bit of the motherboard where plugged in to the psu, is a TTT Grand RGB 750W Gold, why i cant find those cables and buy it, or a pack, why thermaltake doesnt sell them?. my biggest problem is with the pci cables, because it make sometimes my gpu white ligh flashes, and i have to shut down and trying to put in order the cable, them, work it again.