Airtel — Constant drop in internet speed

Hello Team,
I have a broadband connection from Airtel at my residence in Padmanabhanagar. I have been their customer since 2010. From last 3-4 months there has been issue related to the speed and every hour internet is getting dropped and speed is very slow. Download speed is 25mbps and upload is 0.05mbps
Initially I opted for 999 plan where the I used to get around 60mbps and around 9mbps upload speed and when this issue started technician advised saying the line doesn’t support this speed and hence there is drop in internet. Later I changed to 499/- plan where the speed should be around 40mbps
This happened during Aug/sep 2020 time frame and post change of plan still my internet used to drop every hour and it takes about 10-12 mins to get booted again.
Technician did all possible checks and changed modem (twice) replaced wire coming from DP/pole and still issue is same
The backend team are not accepting and very arrogant in understanding the problem and their responses.
they are not coming up proper fix for my issue

In a day more than 20 times this issues is happening and after many tickets and escalations still the same issue
Still they haven’t laid out the fiber cable as well in this area.
I don’t have other options. See attached screenshot of speed.
With this speed how can they expect to do office work ?

Thanks