Based on apple report regarding this issue says this is Geo location based service. Some time your network service is unstable that times comes on iPhone 6S, 6, iPhone 5S, 5 and iPhone 7/ 7 Plus. Are you receiving message your SIM played a tone or any other promotional offers from your carrier based on plans and activation services. This is the common way to fix it.
Beware and stop/ Disable accidental flash message coming on screen. Here I am not talking about company messages coming in Message app.
How to fix Your SIM played a tone on iPhone: iOS 10/ 9/ 8
For this problem we can’t short out by restart, Force restart device. Other smartphone (Android) users may be getting the same message on home screen/ Lock screen.
1: Go to the Settings App on iPhone/ iPad.
2: Scroll down iPhone screen below and Find “Phone” option, Tap on it.
3: Next, Move to bottom of screen and Tap on SIM Applications.
4: Now, First Option in Blue link list should be “Flash” this is the service provided by your carrier. If you are getting same flash message on screen then brows perfect match service and deactivate it.
5: For me I will go for Flash! > Activation > Deactivate.
Screen will ask for confirm “Flash! OFF”, Then tap on Accept.
This sim based settings, Works like Do Not Disturb.
Alternatively, you can contact your carrier provider or customer executive on this problem.
Most of the Flash message types are Callertunes, Internet, Info & Utilities, Cricket & Sports, Games & Apps, Health and Many Other. So we can deactivate any time based on message types that’s you are receiving.
Share my help on stop or Disable “Your SIM played a tone flash message” from iDevice screen. Any helpful suggestion bases on your Experience share in comment box.