Consumer Redressal

I had paid Rs.50,000 for my child admission in nursery in GIIS,Chinchwad,Pune as 20,000 as refund and 30,000 as caution deposit. In March 2015, I had informed the school for the cancellation but school management is not cooperating for the refund of Rs.50,000 and informing that they will pay only 20,000 Kindly help/advice