Injust return/refund policy

I went into Makro on the 28th April looking for a laptop, one of the sales consultants advised me on a specific laptop, I don't know much about laptops so I didn't buy it instantly I compared the specifications of the other laptops on Makro's online site and that laptop seemed better than others, I went in to purchase the laptop on the 30th April, when I took it home I opened the laptop and tested the video function too my dissapointment the resolution was not up to standard! In the adverti*****t online and in store they had conveniently left out that specification. My intended use for the laptop was to use autocad, after I bought the laptop I was informed by a Draftsman that i would need a higher spec laptop to prevent lags. I had to s**** up money that i didnt have so that I could purchase this costly laptop so I did not want to sit with something I was not happy with, I took it back to the store the very next day, on the 1st May, to see if I could get a refund or at least in store credit to the value of the laptop to my surprise I was informed that once the laptop seal is broken they cannot take it back! I had checked the refund policy of Makro and it states software, dvds/video cannot be returned but it does not specify laptops, when purchasing the laptop the cashier and the sales person conveniently left out the part were you cannot return it if it's opened!!!! It seemed like everyone knows this beside the customer because while I was standing for hours waiting for the media manager another manager saw me waiting with the laptop out of the box and passed by me and told me if it's out of the box you cannot return it!!!!! Now I am stuck with a laptop that is very expensive for me and that cannot serve it's purpose, I'm very unhappy with this product!!!! Please can you'll make it know in you'll return policy when purchasing laptops the seal cannot be broken if you wish to return as this does injustice to people who do not know much about laptops.