Fans of Madonnawere losing their patience before the Queen of Pop hit the stage to kick off the North American leg of her world tour, RadarOnline.com has learned. The Material Girl hitmaker kept ticket-buyers waiting for three hours at the Barclays Center in Brooklyn, according to several attendees. It wasn’t until 11 p.m. that she first made an appearance. “Whole arena chanting bulls— at her lateness. Great show but went way too late,” one fan vented about their experience. “I WANT A REFUND NOW,” a second echoed. A third said that other chart-topping performers have always been right on sch…