Pampers premium

I bought 2 packets of pampers premium at Clicks during the special 2 weeks ago, pants size 3. My baby has been using size6 which now is smaller then we bought the pants for the 1st time.i have never seen a leakage like this since I started using pampers last year January,the pack lasted for a week and inside they're many so I decided to exchange the other pack to size6 normal, so disappointing...I'm looking for ther brads I can't seriously