Iphone SE getting No Service issue after 13.5.1

I can not connect to mobile network nor make calls and texts in my iphone SE after updating. Most of the time it shows no service. Sometimes i can see some signal bars but cant make calls with that. Now i can not downgrade myself to 13.5, nobody Responding for this no service issue. Within last month there were 600 posts regarding this no service problem on their phones. Till now nobody resolved this issue.