Bought a 900rand bike she jumped on bike broken

Went into game store for xmas bought all our kids bikes gt home opened it out after the festive so i could teach my daughter to ride she jumped on the bike tried to changed gears n bike broken i caled the store same timeto inform them they say ok no problem bring it in go into store today and the guy tells us come after 21 days n no garantee the bike will be fixed i mean really we also bought a psp hand console game at game it went in fir repairs twice for the same problem n they just keep fixing it until the garantee uo then we must pay for repairs please we have had to many problems with game store and fight a loosing battle i will never buy there again but they need to be sorted out