Pool drain is filled with cement?

If this a newly built pool then have the company that built the pool ~ or the plasterer ~come back out and finish their job of prepping the pool before the start up. Whatever it takes to clear the main drain of the cement is their job and they have shirked their responsibility. If they say they have to drain the pool this then that will be at their expense. There should be no charge for this task and they should also pay for the water to refill the pool. k