I had that issue with an Otterbox case. Bought it, it was bulky but protected the phone well. After 3 years the rubber tore near the charging port. They offer "lifetime" warranty (5 years). Well, wrote them for a replacement and they simply said nah, they don't have that case any more for a phone this "old". So they didn't honor the warranty and just told me I'm out of luck.

What the hell do I buy an expensive phone case for when they can't even honor a 5 year warranty? That was the last Otterbox for me, Spigen was the choice I went with afterwards. Can't go wrong with a 10 buck phone case, I don't care if it breaks in a few years.

When it comes to phones every manufacturer just gives you the finger if it's 3+ years old it seems.