HDFC Bank — Debit some amount without my knowledge

Address:

1/107 Pillayar kovil 1st cross street injambakkam Chennai 600115

I have a salaried account in HDFC bank (perungudi branch). Due to COVID 19 I have so many cash troubles. So I skipped nov and dec month NAVI loan. So my cheque got returned. On dec from Bank, they have charged like ACH debit return charge was debited 590rs as 18 times. My salary was 12500rs. But they have debited almost 11000rs. So I directly went to the bank and asked about the details. They have told that it is not happened from bank, it is from loan side. So I called to the NAVI loan and asked about the debit charges. They have informed it is from Bank side. What can I do? Still I didn't get my cash amount bank. I need immediate refund of 590*18=10800. Kindly do the needful asap. For this month also they have debited some charges. Now my account balance is -6500. I want to know the reason and refund.