Why wont any of my texts send to certain people? ie. radio stations, cineplex

[AC Question]

I can't text any of the radio stations I used to for contests. For example the number is 103939 or 56789. My message turns gray with an exclamation mark beside it but all my other texts to normal numbers work. I used to text these numbers all the time and that screen always appears asking if you wanna go ahead with it charges may apply and I accidently said no and now nothing will work.