Airtel — slow 4g net speed again and again at every evening till dawn

Address:

Bagnan , Howrah,West Bengal, 711303

Dear sir
After lodging complaints here about the slow 4g speed at every evening till dawn airtel previously increased the speed of internet 4g. But soon after they decreased the speed day by day slowly, until the 4g internet is almost inaccessible at every evening till dawn. My number, [protected] is suffering this problem.
Plse penetrate into this matter to wipe out the problem.
Thanks in advance