slat opening mechanism repairable?

[StumpedCanary]

I have aluminium shutters with little winders that open and close the slats - however, each and every one (4) has broken!
As turning they stopped suddenly and wouldn't move at all, when wound with slightly more force something obviously gave inside and now the winding machinsm thing just winds round loose and the slats don't move. Luckily all but one has the slats in the closed position.
They are approx 3 years old and only opened by an adult each morning and closed each evening (there are no children in the house) - should this have happened, is it repairable for me to call the installers? I'd like some info so they can't give me a load of flannel. Any constructive comments more than welcomed. Many thanks in advance

 

[foxhole]

You mean blinds? not shutters?

 

[StumpedCanary]

Sorry for the delay, internet been down. They are aluminium frames with "slats" which open and close - like an old fashioned "shutter"? I wouldn't really call them blinds, they're on the outside of the windows.