I got a call from the Texas State Troopers oc. are they legit?

I have been getting calls from someone that claims that they are from the Texas State Troopers ociation, I told them not to keep calling me; but after a while I gave up and reluctantly told them I would give them a $25 dollar pledge. I looked up this group and have heard that they hire telemarketers to solicit their calls, and that the money donated hardly ever sees the troopers themselves. I even saw a report online saying the same thing. Now they sent me the letter but I am having second thoughts. Can I get in trouble for saying that I would donate and not doing so. I just don't think the ociation is legit. Anyone else get calls from these people?