How can I prevent wear and tear on my Apple Silicone case?

You can certainly pursue this as far as you want to.

As far as what is shown in the images you provided, it looks more like someone tried to remove the case and caused the tear, not that it was just "picked up from the side". It would be a matter of physics ... but, I am only guessing based on what you provided.

Should they? Probably not, especially if new. Can they? Absolutely! Certain conditions may affect the materials used for the case. Like the extreme ends of the ambient temperature spectrum that it is exposed to.

Tears, like this one, are more caused by bending or prying the case from the phone. Note that this particular tear has occurred at a "weak" point where there are small holes that perforate the case.

Could this be a manufacturing defect? Possibly, but according to the OP, Apple rejected that reason. I'm not saying that this isn't an issue with the Apple silicon cases, as we do see a number of posts here with what appear to be complaints about them.

Same thing happened to my case from normal use of pulling it out of my pocket. This is the second time an Apple case has failed me. From my experience Apple just doesn't make a quality case which is a shame. I tried to super glue the case back together but I also ordered a third party case off Amazon for $50 less than Apple's case.

Thanks that’s helpful. So that begs the question: ‘Should these cases break like that when being removed?’ At £49 a pop, I’d hope not.

Okay

Prefect helpful I think it’s nice thank you so much