Airtel — no 4g speed at my location

Address:

Visakhapatnam, Andhra Pradesh, 530008

I have been using airtel since 6 years. There was good coverage and call signals until last month. I had taken the same number's 4g sim in my android phone since last october-17.in the month of march -18, i suscribed for the combo package for both data and calls. Since that day the signals at my home location got so worse. Few normal calls when dialed, we can hear siren and loud disturbing noises. The 4g signal for my data usage is not at all good, that i'm forced to use wifi of another network. I could only use around 5gb since then. Please kindly do the needful network updation in my area and relieve me from this trouble.