4 possible options.
1) order new fans, fix the gpu, replace ALL the fans, not just the dead one.
2) RMA through the place you bought it from, that depends on their warranty period.
3) Manufacture RMA if it's still valid.
4) call a local repair shop and pay through the nose to have any work done. More than likely a 30 day shop warranty against their repairs and labour.
But that boils down to 1 option, get the fans fixed or burn up the gpu.