Fnf withheld

Hi, I took more than applicable leaves (non consecutive) during my 3 months notice period in a pvt bank. All leaves were well informed to my supervisor along with the reason, which were due to shoulder pain and peeping pus from my ear due to hole in the ear drum. Now the hr has with hold my last month salary and relieving letter for this reason. Please guide me is this genuine on the company part or just an excuse to settle a grudge of my boss.