1) you are entitled to refund . there is no provision in your contract that 10 per cent of total cost would be deducted
2) you cna file complaint against supplier before consumer forum seek refund of money paid with interest
3) also claim litigation costs and compensation for mental tortue undergone by you
4) you cna file complaint on your own
5) if you engage a lawyer litgation costs would be more than amount of refund claimed by you