Gift Cards that dont expire, but not recognized by dell websites

I have had few gift cards that i purchased about 8 years ago. Even though i have about 200$ worth of balance left on it, i am not able to get it to be accepted in any of the dell websites. 

It is mentioned on my physical gift cards that the value does not expire. I tried reaching out to the customer service but of no help. I am really unsatisfied/frustrated on how dell does not honor its own gift cards when in the terms and conditions it mentions that the value does not expire.