electrical short 1 channel. Cable spade at fault?

Yes, I tried all the permutations including another amp and it is the YBA R channel.
Sfar,that is exactly what I feared about repair cost vs price paid.

Can I hold the cable seller liable for the tab?

No, you can't.

In the long run, if you want to use these cables, the problem has to be addressed. I have on a few occasions taken cables to my garage and fired up my grinder and filed down ends. Then change to a buffing pad and smoothed out the filing.. Always good results. I can see you not wanting to do this, but I am very handy, built a few things from scratch, modded a few products and built a few cables. This is not an outrageous project. I have also cut off ends and replaced them many times also... Spades to Banana's etc... also, a fairly simple project... Litz is not fun to work with....

Thank you all for your good advice.
I can return the cables.
The real cost is repairing the amp.
I do consider the product defective, and I do hold the seller responsible.

Seller responsible? Rots of ruck!