trendkill

Who, exactly, told you this? Missionaries? Ward leadership?

Had you not been a member for very long when this happened? Did they not give you any warning that you were in trouble before they brought excommunication proceedings?

No need to answer any of these questions if they're too personal. But it seems strange that anyone who was in a position of teaching or authority would tell you that you could do anything you want, and nothing would happen because you could "repent later", and that a member of the LDS church wouldn't realize that excommunication was a possibility for some behavior. I've heard of people who were excommunicated being allowed back in after a few years, but they seemingly have to go through a lot, and excommunication is considered very serious. It would be highly irresponsible (within the context of Mormon belief, of course) to give someone the idea that repentance was a license to sin.