I am so fucking furious at airtel

Aiyo en mandia vedinjirum pola :') I recharged for a year on the minimal pack which has about 60gb data and unlimited calls. I only use data when I am outside since I have wifi at office and home. So wanted save money and bought this pack and whenever I run out of data , I buy the data only pack of 50gb which has a validity of "current pack" plan. Now they have freaking changed it 30 days validity. So what now?!! I have spend 360 every MONTH!!!!! Man these companies really do bite us in the arse and there is nothing we can do about it too.I am seriously considering going to BSNL now ffs!