You missed the cutoff, it will increase next bill. Go back an look at Feb/March, it was probably $0.76 for you then.
I've been waiting for the next iPhones to see if AT&T (or another carrier) offers any kind of super upgrade deal. They have only been offering at best a buy one get one deal which is of no interest to me since I'm just a single line customer. If not I'll most likely be moving to MintMobile (prepaid from T-Mobile).