Pop-up dialog from the SIM card appears on lockscreen

My SIM carrier occasionally sends ads in the form of pop-up dialog, like the ones you get after entering a USSD code. However, they appear on the lock screen too and will keep the screen awake indefinitely until I tap on cancel or close. This has resulted in my phone's charge draining overnight. How do I stop this? I dont want the pop-ups completely gone, just want them to stop bypassing the lockscreen.