TextPlus is saying I bought Remove Ads...I didn't?

I just installed the free version of textplus onto my ipod touch about a week ago. Today, I went to the store to check how many credits different things cost, so I clicked on the Remove Ads button. It says I already purchased it and that it expires June 22, 2012. One problem...I never bought it. Does textplus give you a year free of ads, or what happened? Thanks for helping.