I'm having problems with this right now. So, I purchased my subscription about a week ago (yes, it had long since lapsed). I got my membership code and was all set for presale. Of course, presale has been a disaster. I've literally been in front of my computer since 8am this morning trying to secure half decent tickets (what I'm REALLY wanting is RZ). I finally managed to get some tix in stands, but paid a fortune for them. Got them out of desperation though. Then ordered two more mediocre tix. Felt very unsatisfied. I cancelled one set through Ticketmaster, which left me with a pair. Meanwhile, I STILL don't have what I really want, which is RZ. But, now I'm out of luck, cuz the code is no longer valid, since it thinks I've purchased 4 tix (I returned a pair, so down to a pair). Day continues on and I keep trying and trying, mostly out of curiosity now. Suddenly, at about 4pm, I can now buy GA tix (hadn't been available before), BUT I have to buy them with ANOTHER U2.com membership. Out of desperation, I did it! I then went back to Ticketmaster and returned the second pair of lousy seats (Ticketmaster was kind and let me do that). So, now I'm back down to just 2 GA tix, and two U2.com memberships that I can't so anything with.
I called U2.com customer-service, and explained by situation, hoping they could help me out and reset by code somehow for the two more tix I'm entitled too with the 1st membership or provide a code for the 2nd membership. In fact, I how have 2 tix, 2 memberships, and 0 code access! But it's a no go! Unfortunately, I found U2.com customer service to be quite rude, and insinuated that I'd buy extra tix just to scalp them. If I was a scalper, I wouldn't get my extra tix from buying a membership. They were very unsympathetic and unhelpful.
So I'm up a hill now!