A warm welcome to our Community Forum Sallyloukiki and sorry to hear you're not receiving calls on your phone.
Can I ask whether it's a recent issue and does it happen regardless of where you are? I appreciate it may be difficult to check due to the current restrictions in place, but for example, does it happen when you're at home and at work?
Can you take your SIM out, give it a wipe to make sure there's no dust on it and try it in a different phone to see if it's the phone or the SIM? Apart from receiving calls, are you able to make calls and send/receive text messages okay?
Thanks,
Lisa