serial numbers
HI, i bought a refurbished iPhone x on amazon, everything going great until the last week or so whenever i am on any of the apps downloaded it will jump back and forward to other pages. it also happens when i am on the phone,it will ring any other number i have in my phone,i thought i would buy a new iPhone and trade in the troublesome phone, when i try to do this i get a message thet the serial number does not match the phone. can anybodyy help me here.