Bharat Sanchar Nigam [BSNL] — unnecessary balance deduction

Address:

Kanpur, Uttar Pradesh

Bsnl deducted ₹20/- unnecessarily on 16th june 2018 on my number [protected].
I emailed them with the screenshot and i haven't had any success there.
When i call the customer care they tell me the system is down and ask me to call back later.
When i call them and pretend i want information they tell me the details and their sustems are working properly.
But when i ask them for a refund they tell me that i activated a service mobile radio which i didn't. And then when i ask them to transfer the call to their senior they say that due to repetition of the same statement by you again and again we are disconnecting the call.

I would like the refund of the amount at the earliest.