I would suggest to speak with your networks customer services to have your account checked.
Also as a process of elimination to rule out the phone as the issue perhaps try your sim card in another phone.
If it's the sim card then your network can replace it via a Sim swap @nickynackynoo42
Daily Driver > Samsung Galaxy s²² Ultra 256Gb. Samsung Gear s³ Frontier Watch. Samsung Galaxy Watch⁴ Classic.The advice I offer is my own and does not represent Samsung’s position. I have no affiliation with Samsung.