unacceptable waiting period

Good day, on the 24th of April i was delighted to recieve my brand new Samsung Galaxy S6 smartphone, sadly yesterday(6 May) it would no longer turn on. I then took it to TTS Samsung in Port Elizabeth where i got told to get a proof of purchase from Vodacom, which i did. Upon my return the consultant told me it was not within the 7 day period for replacement(even though it was the 7th working day) eventually she agreed and said they would handle the replacement. However she then followed by saying the replacement would take 2 to 3 weeks. This is unacceptable, if there were repairs being done it would make more sense but why does a replacement need to take 2 to 3 weeks?