Airtel
Change the unlimite plan to limited plan

Hello

here i am using broadband service of Airtel/Tata since last almost 18 months.

i have unlimited plans for downloading and uploading at the speed 1024 KBPS.

suddenly last month both the company has send us the letter that they have chnage the plan

and unlimited plan has change to limited plan . according to the plan new download limit

is 150/90 GBS. after that download and upload speed will be reduce by Half.

now my concern is how any company can do this.

Can you please help my by looking in this.