This usually happens when your iPhone's Message Notification is set on Repeat and there is network traffic, congestion on the sender's location or recipient's location. This signals the SMS to be resent automatically when congestion is over. The solution is to set your Device Message Notification to Never. Here's how to resolve it.
1. Launch Settings and scroll to Notifications
2. Tap on Messages
3. Tap on the options arrow on Repeat Alert and choose NEVER
Since yesterday whenever I call it doesn't ring at all it only shows call ended, for some days now I have been experiencing a terrible network so I did the Apn reset multiple...
