Toner Cartridge Scam???

I got a call yesterday from 'United States Computer Supply' who wanted to send me a toner cartridge for one of our printers at work to try out for free.

The sales rep was obviously reading from a script. Turns out their cartridges are supposed to be better and last longer but they are also twice the price.

She told me that if I was not happy with it after 30 days I could just say so and nothing else would happen.

Somehow I feel I am being scammed. Anyone else experienced this? They do not have any of my info - no purchase order or credit card or bank info.