Airtel — change my circle

Address: 641027

Dear sir,
I bought a Airtel Sim two weeks before.
It shows roaming symbol. I asked customer care they told this is Chennai sim card so it's shows roaming symbol. And they told can't change the circle.
I bought this sim in coimbatore. So please change my circle.
I can't share my data to other no.
Kindly change to Tamilnadu circle