HDFC Bank — Unknowingly deducted amount

I had negative balance in hdfc bank, and raised a request for clearing it and to maintain minimum balance 10000.
Once negative balance cleared one of the hdfc representative called and said it's 0 in balance and i can maintain minimum balance 10000 and it will be not deduct any charge.

But after I add amount to account they deducted 10000 as a charge