Spar Brand Nappies No Good

I've bought a pack of your brand nappies a few days ago and I'm sorely disappointed. I nearlhgy buy all spar products and have always been very happy with them so I thought that the nappies could only be great as well. But sadly no, the fit is just not working and the size? Well my baby is 7kg and the 5-10kg nappy barely fits. The absorption is very bad as after two pees it just leaks everywhere, and soft poo just goes up my baby's back and out the legs. Yes they are a bit cheaper than the other nappies but that money is wasted. Please don't disappoint a loyal spar brand advocate like this! I tried to do this on the spar website but trhe website continuously gives me input errors.