Just follow through with the claim. To give them yet another chance to do the right thing means there is no consequence for acting badly.
Lets see, their response (if any) should go something like this:
"Wow, due to a computer glitch this is the first we are hearing of this issue. We will be glad to send you the parts you have order if you still want them.
Feel free to call us directly if you ever have future complaints."
Any response you get will make it seem like its your fault.
1. they had no knowedge.
2. You don't really know what you want and kind of wasted out time
3. you didn't do what you should have.
To accept their service now will make you seem weak.