Click to apply discount using "I will be using a coupon instead" option?!??!?!

Tried to use Tekkie Town's online shop and get items delivered to my house. There was a special on a specific item that got you a discount if you bought 2, but apparently you have to click to say "I will be using a coupon instead" to apply the discount that is displayed to you on screen... unlike ALL other online vendors. Emailed their customer service department to see if they could assist, but the long and short of their response was it was my mistake and that it's my problem... First, and LAST time I use Tekkie Town.