Added additional test coverage for refund denial
Added additional test coverage for refund denial

ECOM-2583

mferenca/HMS-ecommerce,mferenca/HMS-ecommerce,edx/ecommerce,edx/ecommerce,edx/ecommerce,edx/ecommerce,eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,mferenca/HMS-ecommerce,eduNEXT/edunext-ecommerce