I have the same problem. It's because of sliding the foot while moving to the net, right?
I just can tell you that Yonex SHB-102 lasted almost one year only in this area. Now I have Victor SHB-8500. They seem to be worse in this area. I already can see some abrasion after a few weeks only!
I wonder how long these shoes will last. But I think they won't last longer than the yonex.