The problem may occur due to network congestion on your phone, so please try again in 10 minutes.
However, you can resolve the issue by following these steps:
1. Make sure your phone signal is working well. If not, move to a location with good cell phone signal reception.
2. Turn off the blacklist feature or other ways to block SMS.
3. Put your phone into airplane mode, reboot your phone and turn off airplane mode.
If you cannot solve your problem with the solutions provided, please contact Kodemex for assistance.