Poor online service and customer service

I bought a phone online from you. The phone was delivered on Monday, 23 July 2018. There is a 7 day period in which I can exchange the phone if I am not happy with it. The battery is running off quickly and the phone gets hot easly. On Thursday, 26 July 2018, I took the phone back to the store. Just to be informed that the 7 day period is from the day that the phone was in the bay. How can 7 days be from the day that the phone is in the delivery bay? I never had sight of the phone or delt with the phone. The store manager phones your head office. Your online customer service is rude and has an attitude. I was told I cannot return the phone. There must be a call logged and then they will decide. Your service is bad and I no longer want your phone. I also will never buy online goods from you again. Your service is poor and so is your customer service.