Where is my $300 Visa Card reward for sign up with Xfinity

Hello,
When signing up for Xfinity this year, I was promised for $300 gift card. Now it has passed 90 days and I still did not receive it. 
I tried to reach out to Xfinity via their chatbot, but they do not understand. 
I see this issue and xfinity does not have any customer service phone or email to contact about this. 
This is a fraud and unless I get my $300 got card, I am going to take legal action.

Thanks