My IPAD screen is broken but its working fine. Shocked to hear that ipad screen cant be replaced.

How odd.

If the iPad model is still "in support" by Apple, unless your iPad has suffered significant external damage, it should be eligible for repair by Apple - as you will see here:

iPad Repair & Service - Apple Support

You would be best advised to visit the Genius Bar at an official Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to properly assess your iPad - and advise upon your available repair options:

Genius Bar Reservation and Apple Support Options - Apple

For practical purposes, in lieu of repairing and returning your own iPad, Apple usually exchange the iPad for a renewed/refurbished iPad of the same model and specification. The cost of the exchange is the same as would otherwise be charged for repair. Unless you have benefit of an active AppleCare plan, an out-of-warranty repair while expensive will be somewhat less than the cost of a replacement iPad.