XFINITY MOBILE LINE DISCOUNT NOT INCLUDED IN BILL

I opened a mobile line because of the promotion "free line when you switch to Xfinity Mobile" with an internet plan. I have had 3 bills since opening the account. All 3 bills have included the $30 line charge. The first 2 times I called and/or chatted online with someone, they admitted the mistake and credited the charge back to my card. I was told their capabilities don't allow for the account change to reflect the free line and the matter needs to be escalated. My latest bill has the charge on it again. From what I've seen online this is a very common issue. It needs to be escalated to a department who can fix my account.