Power Hardware advertises new wireless chainsaws for $50\%$ off on its store windows, but when interested customers come into the store and inquire about it$,$ the employee, states that the wireless chainsaws are not available because they're on backorder, but they have plenty of traditional chainsaws in stock. This is an example of $q,$

$$ puffery.

counter$-$advertising

bait$-$and$-$switch advertising

$$ breach of contract.