Employees lie to make a sale

I was told on the phone from an xfinity mobile employee that I would receive 400 visa gift cards for each line I bring over. I waited 3 months, he wouldnt respond to any emails after he confirmed i activated the phones. After I called and reported him, he called me within and hour and said that he just got back that day from being gone for a month and a half bc 3 family members died. The way that man lies, im sure he is lying about that also. I have emails saying I would get 1600 dollars, and it was from the company emails so they should be able to see it. I also requested they listen to the phonecalls. He called back very upset he got called out for his lies. I have a home account and a business account that im canceling if they dont make right the lies that were told. Why wouldn't I trust an employee of xfinity to tell the truth about their promotion.Ive been waiting for 2 days for a follow up. Ive recently seen on reddit other people having the same experience with lying employees to make a sale. Im very disappointed with this company. The service is terrible, dropped calls etc and the home internet is the worst ive ever seen in my life. They are always doing work In the area so the internet so practically off ever other day. My husband said I was crazy to trust their cell service and he was right. The service is bad and the customer service is worst. To lie like that should be grounds for termination. He knew he was lying when he made the promise of the promotion. Im still waiting on my call back