I have inexpensive Weinmann DP18s on my Single Speed.

It formerly had ChengShen 700x28c tires.

I replaced those with Kevlar lined Fxyation tires of the same size with a slightly wider bead.

The tubes have popped four times and each time it's on the rim side near the valve stem. This didn't happen with the other tires.

I'm taking it by the shop for the gadjillionth time. I'm getting really mad. Seriously raging. What is happening?? That's a lot of tubes. A lot of money for tires that I can't return.

Can anyone help??? Please.