NOT ONE BUT THREE DIFFERENT BICYCLES

I have recently purchased 3 bicycles from MAKRO.

Bicycle 1 - Chain keeps slipping off / Brakes didn't want to work - had to take it in to a bicycle shop and pay to get it fixed Bicycle 2 - Seat has completely come off / Brakes didn't want to work - had to take it in as per bicycle 1 Bicycle 3 - Pedal just came off and unable to get it back on.

These bicycles cannot possibly be so fragile?

I have three girls and in no way are they reckless with these bicycles and had their previous bicycles for over 4 years.

So what next? Send them back to makro? I will not pay a cent more to have brand new bicycles repaired. I also dont have the boxes they came in. I'm so annoyed and frustrated. And to top it off, 3 girls are upset that they can't use the bicycles for its intended purpose.

I await your urgent feedback!