Was this "nothing delivery with minimal pace" a Yorker you tried to smash into the next state, by any chance?
Of all the yorker damaged toe splits exactly like this one that I saw over the years, not one (zero! none!) customer ever acknowledged that it was a yorker and they were trying to smash the leather off the ball, it was always a gentle forward defensive or the like...
In this case if the OP is adamant that this damage presented during a cut shot, then I'd argue both of the below points:
1. A yorker was smashed shortly before the cut shot, and caused the majority of the damage, maybe not enough to present itself obviously, but the cut shot then tipped the bat over the edge.
2. The balls being used were cheap/hard, commonly known as the bat breakers. The argument of 'we only use good quality balls' that I hear from lots of serial bat breaking customers is nonsense. The overwhelming majority of balls out there, even league balls, are cheap rocks, regardless of price paid. Only when spending £30 + a ball can you start to say with any certainty that a ball is not a bat breaker. And I'll be honest, outside of professionals, I can't say I know anyone who has even seen a ball at that cost, never mind used one.
It is unfortunate that you are outside the warranty period, but where is the cutoff? If GM make an exception for you and then your mate with a 15 month old bat has an issue, is he going to feel let down for only being a few weeks further out of the warranty than you? Ultimately, this is why I never use my match bat in nets. Taking what I'm assuming is a $1000 + purchase into a net on what I presume to be an artificial surface is asking for trouble.
If the bat traps a ball against the ground (either a compacted hard aggregate base, or more likely in Aus, a concrete base, with some cricket carpet over the top) then the ball isn't going to give way. The few millimetres of carpet will give way but the base below it won't move. The only thing that will let go is the willow, and in this scenario it doesn't matter if said willow cost $100 or $1000 - it is unlikely to stand up to such an impact.