Xfinity [Edited] Gift Card Promotion

We signed up for xfinity in the beginning of January with their "promotion" claiming they would give us a $500.00 gift card 90 days after signing up. We still even have the promotional flyer as proof. It's been well over 90 days since we signed up and no one will give us any answer about the gift card. When talking with Xfinity employees on the phone, they simply just hang up on us because they have no answers. [Edited: "Inflammatory"] our lawyer will now be handling the situation from here.