Terrible service

I have been a customer for years. They were running a buy 1 get 1 free special on t-shirts. After payment, 1 of the t-shirts was suddenly out of stock, yet they will not refund or reimburse via coupon. I have paid the full amount for the order yet received 1 item less. This is incredibly deceiving. Superbalist support staff agree with me, but management wont do anything! Have had to open a case with CGSO.