I just swapped from a 4G plan to a 5G one and now I'm getting this message under my plan details in the app. I don't understand what they mean by prepaid I'm I going to be charged per gig on a unlimited plan till this time period is over? This is a sim card I took out for someone else I don't want a 3k bill at the end of the month. I read all the billing support articles and it says I'd pay a portion of the 4g for how long it was active and a portion of the 5g but why is it called prepaid? 