Dear @Sherri_L_Knox
We’re sorry to hear your AT&T phone was marked delivered but wasn’t received. Since UPS claims it was signed for by someone unknown to you, immediately contact AT&T customer care at 611 / 18003310500 / 18002882020 and report the issue. Also file a claim directly with UPS at www.ups.com/claims for lost/stolen packages. Include your tracking number, delivery details, and emphasize the misdelivery. If unresolved, escalate via www.consumerfinance.gov.
For more information, read: How to file a consumer complaint in USA?
If still need help, reply to us.