Nokia lumia820, I only send one message at a time, but the other party always receives multiple messages? How to solve this problem?

Hi! You can change your SIM card and try sending short messages to different contacts. If the same situation still exists, please back up the important information of your phone and go to phone settings-About-to reset your phone.

Under normal circumstances, the mobile phone turns on the automatic setting (mobile phone setting-date+time-automatic setting-on), and the SIM card can be normally connected to the GPRS network, so the mobile phone will automatically update the mobile phone. If it cannot be updated, please contact the network operator for help or try to replace the SIM card.