Xfinity mobile

In June, I traded in an iphone 15 for the 16. It was an early upgrade two months shy of being pd in full. Offer online taken , paid and trade in phone sent. Received by xfinity and approved as in good condition. Awaiting monthly credits at that time. Now the calls begin to be able to get the credit. Multiple calls and every time agents say something different. The last call today they decided that the monthly credit will not happen bc it is an early upgrade. False advertisement taking advantage of customer. Xfinity customer service is terrible. This is not the first time I trade in phones and it is always a battle. It take months and hours on the phone. Years with them and they could care less. Very unhappy client.