Phone can't make or accept calls

[YaBoi321]

Hi All

So, I bought a refurbished S9 after my old S7 finally kicked it and I've been having some real issues  with making and accepting calls. It seems that whenever I try to make a call it will automatically hang up after one ring and when I try to accept a call it will just hang up as soon as I answer it. I've done everything, including a factory reset and it still does this. Is this problem fixable?

[Anonymous User]

Hi.
you may need a sim replacement for your network provider.
Hope this is help..

[Rzee]

put it on aeroplane mode for a 20 secs then take it off and see if it improves.

otherwise call your provider. I had the same problem.