Airtel — ir pack charges

Hi,

I'm charged by Airtel for IR pack which I never requested.
I traveled to Austria and Hungary on 28th April, 2019. I called Airtel customer-care number on 23rd April to deactivate All roaming packs from my number and enable only basic roaming pack.
I again called on 27th and 28t, April 2019 to follow-up on same. Before leaving India I double confirmed that IR pack was not enabled on my number.
After 8 days when I returned I found that Airtel has enabled IR pack of INR-3599+GST on my number without my knowledge. I immediately called customer-care number to rectify the issue.
They told they can't do anything until bill is generated. I got my bill on 18th May, 2019 and I again called customercare number, From that day I'm following-up with them with No resolution to my issue.
I even sent a mail to nodal-office and I received the response that I requested IR pack on 29th April, 2019. I was not even in India on that day.
I'm spending atleast 1 hr daily in talking to Airtel without any solution. I'm in Mental stress now, due to Airtel's responses.
My outgoing and data services are discontinued, even though I paid (Billing amount - IR_charges).