Vodacom faulty Samsung J4 core

I bought a Samsung J4 Core at Pepcell 20/12,I started using the phone on 25/12 on the 26/12,I tried to charge the phone and it wouldn't charge I tried to charge again on the 27th because battery was almost dead.On the morning of the 28th I returned the phone to Pepcell and was told as per Vodacom policy they can't refund or replace the phone because I returned it 1 day late, although it was Christmas weekend!!?? What angers me is the saleslady tells me that she never recommend that brand because customers have been having problems with the batch they received.Knowing that there's a problem with the product they continue displaying it and when I paid for it the other saleslady didn't say anything!!! I desperately need my phone for work and just want my money back, before work starts on the 4th!! Please help!!