I need help soon

[Shrekd]

I need help cause my phone is not allowing me to make calls and of people try to call me it will ring but It won't show up on my phone please help

 

[Jen_Sai]

Sounds like a dodgy sim or iffy service (signal etc)
Last month my 12 year old sim finally gave up the ghost so I had to get a replacement, unfortunately nowadays they're multi purpose sim cards (ie: standard/micro/nano) so last week it stopped working again.
I had to take it out and re snap it together before replacing it in the phone, worth a check?