where to file a complaint?Defective laptop cannot be returned

Hi everybody, my friend had just bought a defective laptop from Sofitel, They told her that it is new, the wireless is not working and with warranty.. The shop from the Sofitel told her to go to Redington for her laptop to be fixed, They told her that it is brand new but when she started to use the laptop is was first used by another person.--- She cannot used the wireless because it is defective, May I just ask where to file a complain about these shops saying that they're laptops are brand new but it's second hand and somewhat defective? -where to complain about these issues??..Please help. Thank you..
Caution: to all people also please be cautioned about these second hand things.
that's the reason people say that u should not buy expensive things from smaller shops just to save few bucks .. things like this always having problems and need to be fixed .. if you have proof that it was used before then go to the same shop and show to them.. anyway they should replace the laptop if its is having problem within 3 days after purchasing..tell them u dont need to repair it as its new and you need to exchange it or you would file a complaint in consumer protection.
hi
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