Is it the sealer thats bubbled, if so it will turn white and can be fixed by stripping and then resealing which as to be done when its dry. the builder should carry this work out at no cost to yourself.
If the concrete as bubbled then you need to get the builder back to see what can been done.
The concrete thats used for this job should be P300 fiber entrained to stop any cracks or bubbleing.
Also expantion joints should be cut every 10 square metres
