Out of box Failure

My daughter bought a Samsung Galaxy A31 Cell *** on the 4th of July 2020 at the Cell C shop in the Walmer Shopping centre in Port Elizabeth and on the 5 of July she took pictures from her phone and found that was blurry and that the battery turn extremely hot when charging , she contacted the sales person via whatsApp (Megan) and told her what happened, she also send Megan the pictures for proof of the failure. Megan told her that they are closed because of Covid 19 and need to take the phone to another store, my daughter went to Bay west Mall and she was then told that the phone must go in for repairs, she told them it was brand new, she than told the person in that store that she rather go back to the store where she bought the phone. She told Megan that she will wait until they open so that she can assist as she is the person that sold the phone to her. The store open on the 20th of July again and my daughter went back to Megan, she was than told that the phone must go in for repairs as its over the 7 day report date for exchange, I was furious as we report the matter to the store and explain to the manager that this was an out of box failure. This is an R400 monthly contract that we was happy to sign, and now they repair the phone and do not want to replace it, because of the time frame when it was handed it in, first it was not our fault if they closed the store where we bought the phone, and that the second store want to send the phone in for repairs. This is not fair in the way this Cell C Walmer store tread us after the contract is signed, I want this phone to be replaced asap with a new phone and if not, then please be insured that your account will be blocked, I will not pay for a second hand factory fault, I will go public and legal with this matter , Jaco ***