Disapointment with Sales

I started a recent CS chat with the following:

I wasn't told this coupon was going to expire when I purchased my computer ( MJNPJN5?X7LZW1). I just went to use it and found out it was no good. I feel a little betrayed because I thought I was getting a coupon that would be good until I used it. The guy on the phone talked me into an extended warranty based on getting this coupon and never said it would expire. I am ready to buy a television, can you please give me an extension so I can use it?

The answer was no, twice, and I am out $100.  Very sad, I will have to take my business elsewhere.