Mulfunction of brand new Boni 3 wheel stroller

I purchased a Boni 3 wheel stroller at the toysRus welkom branch. In less than i month the front wheel of the stroller wouldnt move at all. I took it back to the branch and they supposedly fixed the wheel , within days it was stuck again. I cant use that hazard of a stroller... i wrote them an email and went back several times to their branch but no help! I need my money back or something i could actually use that works and is safe!