Airtel — data theft by airtel company

This to report that iam using airtel since 3 years and getting my data balance deducted out of nowhere even when my data is off from hours they are messing me that i have used my 90% data. Thats so unloyal of airtel with their customers. I complaint about it a month ago.. They some how resolved it. But now same thing is happening again my 3gb per day data plan is vanishing so quickly in a blink of eye. I hardly use whatsapp and insta with no video seen and message pops with 100%usage of data. Iam calling customer care from almost 3 days and they are talking like # with no specific details and solution to my problem. Do something about it.