Bharat Sanchar Nigam [BSNL] — high and hidden tariff

Address:

Golaghat, Assam, 785621

I have activated international roaming facility on my bsnl mobile no. [protected] on nov 7th 2017. I used the number for some of my calls while in abroad from 10th november.
The connection was stopped abruptly on 22nd nov without any prior notice. On enquiry it was revealed that my bill has risen to rs 69000. And the tariff was also revealed only then. They told me that the incoming call cost is rs. 2700 for eight minutes.
My complaint is that they should have stopped the facility once my bill was about rs 10000 as i had deposited an amount of rs 5000. Also the tariff should have been clearly mentioned.
Or atleast there should have been a prompt about my bill before letting it rise to such a high price.
This a fraudulent behavior on bsnl's side.
I request you to kindly look into the matter and provide a resolution.