What the .... is wrong with this thing!?!?!

My battery on my 32GB 3G S is going crazy. It was at 80% and I made about seven short phone calls. I looked down and it was at 19%!!! I get on the forums to do some research. About 10 min later i pick up the phone to make one last phone call. After I hang up the battery jumps to 54%....

Should I calibrate the battery or whatever people are saying or just return and get a new one?

Do you think has a recall in our future? I hope not.