Xfinity Mobile does not honor anything

I signed up to Xfinity mobile for the promo of switching and bringing own phone for 200$ gift card. I signed up one then after a second phone in hopes of getting the giftcards promised. I have called Several times and three times the issue was escalated with no resolution. This last time I spoke to an agent where the call center is from COLUMBIA! The agent that answered after no resolution I asked for a supervisor and he stated “I am the supervisor” and I was appalled like since when does a supervisor get on the line ? I asked him for someone above him he said there is nobody above him. He just stated I’m sorry the agents didn’t give you correct information but I can’t bypass the system the account is not eligible I can’t do anything else IS THERE ANYTHING ELSE I CAN HELP YOU WITH? I’m like but you didn’t help your the first agent to give me this info. Every other agent stated they would escalate to provide me the gift cards since they made a mistake but now this!!  I’m just so irate with Xfinity mobile they make so many promises to get you in then make us go through all this. I KNOW what incentive I enrolled for. First off I switched and brought my own iPhones over and it’s almost a year with this. Agents on phone will not help and chats all of a sudden disconnect and then we have to repeat all of the problems. Terrible