VEry unhappy with my 24 hour bra?

I have been buying the 24 hour bra for many, many years. I bought two when I was in Virginia (I live in New Hampshire) BUT the straps SLIP. I set them just where I want them and within 20 minutes they have moved and I have to keep pulling them up off of the upper arm. VERY UNHAPPY as they are NOT cheap bras. I did see where they were made in Thailand. I thought they were made here in the United States. Now I don't know just what to do. I am back using older ones that I have kept. Any suggestions??????