NSW False Advertising and Australian Stock Horse Purchase

I recently purchased a mare advertised as a 2 year old Australian Stock Horse, broken in and going well.
Currently 14.2hh and to mature approx. 15hh.

After researching her branding, having the farrier out and booking her in to the dentist. It looks like she is around 4 years old and was possibly started as a buck jumper.

The lady who I purchased her from said she has no idea that the horse supposedly was trained as a buck jumper (had her 12 year old daughter riding her) and offered me to swap the mare for another horse she has for sale but won't give me back the $3000 I paid for her.
($2500 cash and $500 bank transfer).

Where do I stand legally on getting my money back and not a swap…..??
I have screen shots of all conversations online.

Thanks