S21 Phone battery life

Good day, I am reporting a very poor customer service that I have just been through. I purchased my S21 brand new on the 11th of Feb from Vodacom in Mall at Reds, here in Pta. Then I realized by the 12 and 13th, that it is not keeping battery power. So I tried to make contact with Samsung, but found it extremely difficult to get through to the live chat services, so I phoned Samsung and last night, just before 8p, I spoke to Shirley, and ref no:*** was given to me. The issue was explained to her and she said that under no circumstances must I allow Vodacom today, to just take my phone in and I have no phone, as it is within the 7 days and I should get a new unit completely. I understood and just now, when I went into Vodacom and spoke to the Technician, Estian and the Manager Dee, I was told, the phone must go in first to the service centre and they do not know how long that will take. We contacted Samsung again and the Vodacom manager spoke to a man who answered, and ref no: *** was given. He had such an attitude and this is very disruptive for me as a customer. I do not see why you cannot take your faulty unit back and investigate, why you want me to be without a phone in the meantime. You should have assisted Vodacom with a ref number giving them permission to give me a brand new unit and you can investigate for surely, your faulty unit. You are the manufacturer, not Vodacom. So far, no response from any party. I have logged this onto Samsung site and Vodacom as complaints.