Galaxy A51 has no service anywhere, even right under tower!P

[PDS]

Please help! On April 22, my Galaxy A51 suddenly said it had no service anywhere. Even when I went and stood right next to a tower, where I have always had full 5 bars, 100% service before. I have tried to turn off the phone and restart it, and that did not work. Next I tried putting it in airplane mode then back to normal again and that didn't work. Then I tried removing and replacing the Sim and that did not work either. It still says that there is no service and that my message will be sent as soon as the phone detects service. I checked my account and I have over a year of service left, over 3000 minutes of talk time and 5000 texts but only 750MB of data left. Why is it doing this? Does anyone know what else I can try to fix this? Please Help! Thanks for looking.