Pretty little Liars insider texts?

I signed up for it once and it kept sending me the same thing over and over again. So I sent "stop" and then signed up for it again and now it's fine. But it's a different number this time. First it was 462223 and now it's 21534. I looked it up and the right number is 21534. So why was it different the first time? Did this happen to anyone else?