heartbroken at horribke service

my service has been off since the 15 March 2022. made the initial effort called the support contact center did some trouble shooting. i could not set the APN, tried rebooting the phone nothing. changed sim cards, other sims worked in my Galaxy phone. had no service the whole weekend. on the 22nd i called the contact center again, now my APNs are set but still no service, the lady i spoke logged a call. coz she tried and there was no service. i also logged a call and today i get a call from RAIN. Nothando decided not to listen and read her scripts. told me my phone is old i need a 4G phone.was not willing to listen when i asked the question as to when did this become a thing as i have been using this sim in this phone since i had this sim. she told me their sims work only in 4G phones. then hanged up. i am not sure if i need to go buy a new 4G phone to use my R250 service on their network. that has been working.