Airtel — data usage malpractice

Website:

www.airtel.in/mobile/prepaid/tamilnadu

I am using airtel 4g prepaid sim in a airtel 4g datacard. I have recharged for 56 gb data/ 28 days. I didn't have any issues for the initial few days. Afterwards it always connected to 2g network and data loading was dead slow. Each day i have call the customer care rep and they won't resolve the issue. They transfer it to senior excutive and they will say as i have used the full 2gb data for the previous day, it is not activated for the next day. They told me they will activate, and it will be connected to mostly 3g afterwards and this happens like four or five times. It was happened again and again. Ultimately today they said i have used the 2 gb data for day, though it was connected to only 2g network for the whole day.

It seems they cheating people technically. Because i don't understand why it is not connected to 3g or 4g and how they could activate from their side, if they are not blocking my data usage.
Kindly resolve this issue otherwise post this on every social media and if possible i will file a complaint against this.