Unhappy customer

My bf bought me a asus PC 2024 July and we did everything they said we should, I went to take the PC back because the warranty is 3 years but a lady at Menlyn refused to help us because we didn't have the certificate but we had the receipt. We did apply for the certificate the day it was bought, we also have an email proving that we sent it but they refused to help us, and I need my PC serviced.