Charged for device that was returned to att

I received a text message stating that att has not received my phone by April 1st and it would be charging my bill. I shipped the phone on the 22nd of March and when I checked the newgistics/tracking website it shows that the phone was Scanned in grapevine TX and then delivered on the 28th in fort Worth TX and then in transit back to grapevine TX. I am being charged for the phone when it clearly says it’s delivered and it’s very frustrating. The rep that i spoke to said they can see it was delivered and shipped before April 1st but since it has not been scanned in that’s still considered not having the phone sent on time. I asked for some type of credit since they can see that it was delivered to their warehouse before the  4/1/18 and the rep stated that once the phone is scanned in they will ship it back to me. Very frustrating considering that i have 4 lines with you guys and have internet and uverse services as well. Seriously considering switching services because this is ridiculous. Been a loyal customer for over 10+ years and att could not provide me with any type of resolution whatsoever or provide my bill with the $253.00 credit.