Terrible service

I bought my son the lightning Motorcycle which u now have on special. He only opened it yesturday to find out it does not work properly. The motorcycle keeps falling to the one side so it does not ride properly. I phoned the tygervalley store where I got it and was told without a slip I cant exchange or refund. I unfortunately somehow lost the receipt. But this bike is brand new out the box. It's a factory fault but now I'm told I can just throw it away like i threw my money away at your store. This is the first toy shop that is not even willing to exchange it. If that's the case il never support u guys again. And I will put my complaint on all social media. Now I have a very unhappy birthday boy that does not have a birthday gift as u guys sell ******* toys.