Received a brand new phone that didn't work properly

I recently upgraded from the Samsung A53 to the Samsung A54, but since receiving it, I've encountered two persistent problems. Firstly, voice notes aren't recording properly; almost every attempt requires multiple tries before successfully sending a voice note, leading to frustration and wasted time. Additionally, I'm experiencing numerous issues with WhatsApp and internet connectivity. Calls suffer from frequent silent interruptions, making it extremely difficult to hear the other person, and this happens consistently regardless of location. When I call the same person from my wife's phone, the connection works perfectly, indicating that the issue lies with my phone. I reported this problem the day after receiving the phone, but was informed it would need to be booked in for a couple of days, which isn't feasible for me as a financial adviser, as my clients rely on my constant availability. I'm unsure how to resolve this frustrating issue with my new phone, which is really frustrating.