These scams have been going on for generations... Grinding wheels, drill bits, you name it.
Back before Caller ID, I used to delight in torturing them like this......Answer the phone, it's "them", so listen to the first 30 seconds of the pitch. Interrupt them by saying that you're REALLY interested in whatever it is they're selling, but that you need to turn your welding machine off and you'll be back in just a few seconds.
Then you lay the receiver down and go do something for 30 minutes or so. After an application of the big wait a time or two, they didn't call so very often anymore.
Arguing with a Kansas State fan is like playing chess with a pigeon.
No matter how good you are, the pigeon is just going to s*** on the chessboard and strut around like it won anyway.