Airtel — 4g network not receiving from few days

Address:

Karimganj, Assam, 788710

I live at assam, karimganj district where i used to receive 24hrs high speed 4g network so i recharged with an amount of 399 i. E. 1gb/day for 70 days... But since one month i am unable to receive 4g network.. Whenever i switch to 4g (Auto), the network shows 3g then 2g then data connection lost... Why so???
Its been happening since last one month.. Please review my complain and try to fix it... My number is [protected].. My money is going in a waste.. Whether fix the issue or else return my 399 rupees.. Thank you.