DALLAS, May 16, 2011- Plano-based Alliance Data (NYSE: ADS) has extended its commitment to support Children’s Medical Center through a four-year, $600,000 contribution. The donation, which will bring the company’s cumulative donations to more than $1 million, will support the continued growth of the Children’s at Legacy campus as hospital needs dictate, and through community events like the Children’s Medical Center Holiday Parade and the Red Balloon Run & Relay. Additionally, Ed Heffernan....