Wear? I've never heard of a sim card "Wearing out". Dropping connections doesn't sound like a sim card problem, it sounds more like an account issue.

Sims either work, or they don't. If I were you, I'd look for a different culprit.

"Sim cards" are also the number one thing operators blame when they can't fix an issue. There are only a few things that can kill a sim, incorrect pin codes, puk codes or using it in a sim cloner will kill it, not using it in a USB modem. When a sim dies, it's gone for good. If the USB modem "wears the sim out", it's a physical thing and it would involve actually damaging the gold plated contacts on the card, but even then the sim would either work, or not work. Replacing the sim every month won't fix this, replacing the modem will.