Dissatisfied customer service

I am utterly dissatisfied with the customer service I received at the Game Store in the Garden Route Mall. Someone purchased a 3 wheel pram for me there I'm September 2015. My 4 month old baby fell out of the pram in December,. I found out the front wheel was problematic. After many attempts of getting the slip from the person who purchased it. I tried to return it on Saturday. After explaining to the manager that I'd like a refund or exchange it for the 4 wheel pram. She says the only thing she can do is replace the wheel. Tell me, what's the use of fixing the wheel, if it breaks again. My child falls out, the fix the wheel. And the cycle repeats its self. Why won't they exchange or refund it. Prams are supposed to be safe. If this is the type of service Game gives to mothers. I'm sorry, I'll spread the word. I'm disgusted man! A child's safety is at risk here!