I buy about 4-6 12 packs of Pepsi max a week. The last two times, they are all flat. I just recently bought a 12 pack of Pepsi and I cannot believe it-IT'S FLAT TOO! All of these packs were well within the date. I've spent so much money in the last 3 months it's inconceivable that all of this product is bad. I've called and Pepsi sent me vouchers for 4 free 12 packs. I used them and bought Pepsi Max. ALL FLAT! Why?? I'm done. Coke zero tastes great and I'm sad I didn't try it sooner!