xperia go repeatedly terminates calls

[bart]

Hello I have problem with new xperia go.   Suddenly breached phone calls spontaneously when I hold the phone by the ear  - some times each 10 seconds some times I can speak  6 minutes without any breach. But it happen several times in day.  I downloaded latest actualization yesterday but I doesn¨t help. 

[Johan]

Are you able to replicate this using another SIM card in the phone as well? If not I suggest that you contact your network operator to get a new SIM card.