Don't give up on the Paperwhite. Its the best specialized eReader at the present time. However, its obvious that the REPLACEMENT route is a dead end especially with our INDIAN support team.
Instead, just process the refund as a defective unit from the Order page and you get a full credit for shipping to and from you.
Then just order a brand new Paperwhite from the Amazon product page. The odds are HUGE that the new unit will be great.
It appears just the replacements are a disaster. Probably, they are just sending out other folks' returns to new requesters hoping the new customers won't notice. They may not have enough new stock yet to really satisfy the demand.