invoice copy request
I bought second-hand IPhone 5s in 2016 in Puerto Rico with no loanes and successfully unlocked it from ATT.com website request. Now I lost my own AppleID password and need to recover it with AppleCare but they want invoice copy, seller tell me that invoice was electronic and his ATT login/password and phone number are lost. Can You tell me information about ATT store where phone was bought for further contacts for invoice copy request? I have information about IMEI,SN, date of purchasing.