Prestige — roti tawa; stick chappaties

Its about 10 days, i bought a roti tawa. But i am not satisfy with this product as the chappaties get stick with tawa while cooking and also after once use it turns to dark black like iron tawa. I got to the retailer from which i bought it and he adviced to wash the tawa just after cooking. But it is very hard to wash hot tawa as it burn the hand. It takes long time to wash and get back into original coating.
I am very disappointed with prestige.