Not receiving texts from someone I unblocked?

I have the iPhone 5s and I blocked someone from sending me text messages and calling me about 3 months ago. Then a couple weeks ago I decided to unblocked them. In my settings it says I have no one blocked but I'm still not reviving text messages from that person when I know they have been sending them. Has this happened to anyone else? Does anyone know how to fix it?

If you don't get the message, how do you know that have been sending them. Just because they say so? If someone "blocked" me for no good reason (I'm assuming no good reason, because you have now taken them back), I would think, "if I'm blocked, I'm outta here." There would be no more message from me.