My phone just went sos mode and T-Mobile can’t help assurance won’t help

If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support

• Check your coverage areaIf you see SOS or SOS onlyIf you're on AT&T's 3G networkRestart your iPhone or iPadCheck for a Carrier Settings updateTurn your cellular line off and back onReset your Network SettingsUpdate your iPhone or iPadContact your carrierGet more help
• •Make sure that you're in an area with cellular network coverage.
• •Turn cellular data off and then back on again. Go to Settings, then tap Cellular or Mobile Data. If you're using an iPad, you might see Settings > Cellular Data.