Long term loyalty repaid with horrible service

Since Vodacom no longer has a working e-mail for customer complaints, I've decided to share my disappointment here:

I've been a Vodacom Customer for probably close to 20 years now. All my contracts are with Vodacom; my phone, tablet, wife's phone, home internet and laptop and I've always been very happy with the service I received.

However, I am really unhappy about the customer service from Vodacom after a recent upgrade. I upgraded to the Samsung A56 and have been so disappointed in this phone. It's slow. It lags. The battery is horrible. And on two occasions now I've unlocked the phone to find a message that says: "System UI has stopped working" (or something similar) and then it takes ages before the phone responds again. I'm not a gamer. I use the phone for ordinary tasks - phone calls, messaging, social media etc. and yet this brand new phone is giving me all sorts of problems.

I've reached out to find out if there is any way I can return the phone and upgrade to something like the S24 or S25 Fe which supposedly has better performance, but I've been told that I'm "outside the cooldown period" and that getting a different phone is not possible now. So this means I'm stuck with this phone for the next three years. If it's starting to give me problems now, what's it going to look like three years from now? I don't care if I have to pay significantly more for a better phone, but I need a phone that works.

For the first time in all these years I'm considering moving to a different network once all my current contracts have expired. This is not the kind of service I'm used to at Vodacom.