Replacement Brushes for Electric Spin Scrubber

I would like to take advantage of the free pads and even purchase another ser of brushes. I purchased the tool on this past Monday and used it on Tuesday.
My wife's love language is cleaning, she'll be happy for a week. This is because she observed me cleaning the shower and floor with the tool. I'm gadget guy and I will clean better if I have a great tool. This is a great tool. Easy to put together, simple to used, and the power of the brush even excited me. Sleek design with quality look. No batteries required! This what I have been looking for.
So I hit your QR code and noticed you even offer free refills on pads. I wanted to include more brushes, but your shipping charges scared me away.

Thanks,
Happy Home Cleaner