Ice build up normally indicates the door is not sealing properly, the doors have been opened and closed frequently or the doors have been left open for a long period. Inspect the door gasket for to be sure the door is sealing all the way around the perimeter of the door.
If you continue to have problems, please contact Haier Appliances at 1-877-337-3639 or visit https://www.haierappliances.com/support/schedule-service to arrange service.