Unfair credit card practices

I had accumulated a lot of debt on my credit card. I transferred the balance to a lower rate to pay the balance off. I was reducing the amount by making 500.00 payments per month on a minmum payment of 200.00. I didn't notice that the credit card company changed the grace period from 28 days to 20 days and that caused my payment to be late, which automatically bumped the interest rate to 26.75% ! I will never be able to climb out of that hole when my minimum payment due is now 600.00! That is much more than I can afford.I feel that these companies do that to consumers to cause slip ups that would make us default on the agreement. The money that they make on late fees, over the limit fees, and compounded interest on high rates is astounding. I am shocked that with all of the consumers that have been forced to default on ARM loans, causing a lot of foreclosures and people filing bankruptcy, that they would not want to encourage more of that.