Unapplied $400 Phone Promotion Discount on Account

I am writing to formally dispute an unapplied promotional discount on my Xfinity Mobile account. Five months ago, I purchased a new device Iphone 17 Pro Max under an explicit promotional offer for $400 off.

According to the terms of the sale, this discount was supposed to be applied to my account as a monthly bill credit. I have placed this order with Xfinity phone call agent & he confirmed me that I am eligible with $400 offer & I placed the order, However, That monthly promotion was never applied to my account because the CC agent did a mistake & didn't applied the promotion properly. Then I need to call every month to CC team & they applied monthly credit manually. However I have just been informed by frontline customer service that I will not be receiving this monthly discount on my bill going forward as Xfinity rules has changed. The CC manager told me that they will take the action against the CC person who placed my order. But in this chaos I am loosing money with so much mental stress & monthly calls with CC.

I have met all consumer obligations for this promotion and have kept my account in good standing. This sudden removal of an agreed-upon promotional rate constitutes a billing error.

Please route this complaint to an Enhanced Care Management (ECM) tier-3 representative or a corporate escalation specialist to review the campaign requirements active at the time of my purchase. I request that the action needs to be taken immediately.

For security, I am ready to provide my account number, phone number, and billing address via a secure private message upon request.

Thank you for your prompt attention to resolving this matter.