Tires: broken tire valve, front wheel alignment, hub cap

Question
Hi,
The right front tire valve has been sliced off twice. The service tech tells me it's the hub cap but I have switched all of them around and it's only the right front tire that has this problem. When the hub cap is on, after driving awhile, the valve is so tight against the opening in the hub cap that it will slice the valve again. I have a 60 day warranty that is almost up and I don't want to pay for a repair after the fact. Do you think it is a dented rim or the axel? Could it be the front wheel alignment is off balance? I wouldn't know, friends have been telling me these possibilities.
I am getting nowhere with the car dealership.
Please advise, thank you

Answer
There are a couple of possiilities.

One is - and don't be offended - do you frequently bump a curb with the right front?

The other is that the wheel cover is not tight enough and it is moving inside the rim.

I don't think alignment and balance are issues here?