Faulty girls bikes

I bought 2 bikes for my girls (2+3 yrs) during 2018 Black Friday deal. I December i had a problem with the extra wheels and was told they are not under warranty and also told they do not sell them. So i bought them elsewhere. Then in January the second bike had the same problem of which this shocked me. Now both bikes have a problem with the chain that is always loose and the breaks. I took them to Game in Vincent and was told the chain is also not under warranty. I was never informed of that because when i bought them, the sales guy who assisted me recommended the bikes. Why is Game so cruel. This is not the first time i have an issue with Game items. Am gonna right to the ombudsman for advise on this matter.