Non-compliance with the CPA. Won't refund "items they don't usually stock"

Bought a mouse online as advertised on Google from them. I collected it and upon taking it out of the box, I found it to be unsuitable. I returned it the next day and was informed by the manager that they wouldn't return it as it "wasn't a product they usually stocked". After informing him that that isn't my problem as it was advertised all the same and the CPA very clearly states that we as consumers are entitled to a return, rep**** that I should take them to court. We'll see what the National consumer tribunal has to say. I'm just thankful I didn't spend more. Buyer beware!