Unless there's accident damage, if the mirror is just six months old, it should be covered under warranty.

Warranty is to protect against unexpected or premature wear of the vehicle.

Tire wear is expected, that's not covered by warranty.

Suspension noises after a few months is usually not covered, but sometimes, warranty covers premature shock failure.

Light bulbs popping after a few months will not be covered... as bulbs burn out.

But side mirrors? Those should last at least two or three years before a motor gives out.

Ask to talk to the manager and complain that side mirrors on your other vehicles don't wear out this quickly. Talk to the right person and they should give you warranty service.