Carrier message showing "N" in contact name.

[ZKnowN]

Hi guys,
I am using Lenovo A1000 and today received a message from my bank and instead of the bank name as the sender it just shows "N". Other messages are fine and I'm using the default messaging app for Android 5.0.
I also received a message from carrier and It shows "NN".

Please suggest a fix.

Thanks!