How Ackerman's ruined Christmas

So i bought two cellphones from ackermans canal walk last Saturday just after miday, it was Christmas gifts for my daughters, i however took the wrong phones and went back this morning at 9:45 to exchange it for more expensive phone's and was met with Lydia that tells me its 8days later and they cant exchange it, technically its not even 7days later due to the time, she called her manager Dashing cause to confirm and he told refused to assist, i advised them i do not want the money i just want to upgrade my purchase but they did not want to assist and told me about their policy which by the way i did not sign on the slip nor was i explained when i done the purchase so this does not make it a legal contract. I am appauled by the lack of service and management thinking they can make their own rules, i will not use the phones as i expect Ackerman's to assist me, with covid and everything happening in the world it would never nice to get respect and assistance and not get stressed out by a shop i have been supporting for years. My kids is sitting without a Christmas gift cause you chose not to assist me , i would like this matter resolved