Xfinity visa gift card expired please help to extend it or reissue it

I was having trouble activating my gift card for several months and it just got activated like few weeks ago through phone and today I tried to use it somewhere and noticed that the card has expired already just few weeks after being able to activate it. Please help me to get the gift card reissued as there is a lot of balance on it, I did not even expect it would expire just weeks after activating it. Please help me.