[Q] (help) sim card full message but no contact/messages on sim card storage topic

Hi.

I have recently gotten a tmo galaxy note 4.

For some reason, I started getting

'sim card full - please delete messages on sim card storage '. Every 30 minutes.
But when I checked, there were no messages or contacts for me to delete.

I searched on Google but it seems like only solution puerile aww giving is just to delete messages.

Does anybody know a fix for this issue? Or any experience? Thanks.