ACT Fibernet — fake usage of data

Address:

G1, 59c, SOWRNAMBIKA APARTMENTS, 7TH AVENUE, BANUNAGAR, PUDUR, AMBATTUR, CHENNAI, Chennai, Tamil Nadu, 600053

I have been using my act fibrenet for a year and my package is 200 gb per month, things went good for the first year. Now, in 2019 january, act costumer care said that the my package will be provided with 1000 gb with additional just 100 rupees every month so i felt good and i changed my plan.
First month i saw my usage was high and i couldn't beleive so i changed my password frequently so that other people seeking free wifi's won't get it.
For the second month, the situation is the same and the usage was like 160gb one day, and my usage will be around just 10 gb. This really is a serious issue, my first year my usage of 200 gb gets over at the 24 or 25th day but now it's 160 gb a day seriously!!.