If i go to best buy and exchange a wireless router and then i go again to ask for a refund?

-hi there i just bought a wireles router for myself but the first one was too complicated not enough feature then i went to best buy to supposedly get a refund but then the person told u could get a exchange and i said ok but now it seems the second router i got now cant even get connected in that case does any one know if i can get a refund even though i exchange it for another? before the 30 days? or 14 days?