I purchased an additional year of PS+ via the store this morning, in order to take advantage of the 15 month offer that's being offering. I was charged and received the confirmation email, but my sub is still showing as expiring in May of 2013 both in account management and the email that I received. I've been a PS+ member since 2010 and this is the first time I've had an issue extending my sub. Both times I renewed before the auto-renewal kicked in, so I'm confused. Am I going to have to call the support line?
When I renewed mine it showed up immediately in the services list with the correct date. Same with when I won a code for three months free. Yes, I'd suggest contacting customer service. Have a copy of the confirmation e-mail handy.