Pampers Nppies Baby Dry Jumbo Pack various sizes £12 at ASDA

Found a large number of bpoxes of Pampers Baby Dry nappies lying near the entrance of ASDA, Clapham, London. I only concentrated on size 4 as that what our baby needs and these boxes contained 120 nappies each for £12. There were other sizes avaialbale also. I definitely saw size 4+ and 5 as well but cannot remember the number of nappies in each.
I cannot see the deal online, so it might be store specific but that box size is not usual; maybe they are special offer boxes