Airtel — sim services stopped working

Today from last few hours m not getting any sim services on my postpaid airtel number. I am currently traveling outside of india and my international services were activated, sim was working fine till last few hours but all of a sudden it stopped working. I cannot call the customer care as well since i do not have any other number. I have tried restarting the phone, cleaning sim slot and manually selecting the network but nothing works. I am stuck here without any calling services. Request you to look into it urgently.