Nedbank and scary interest

2017 August I made a personal loan with Nedbank of 67000Rand the interest wasn't over 22% if I remember correctly. The loan was for a period of 72 to pay it off my installment was 2400rand pm. So since the first lock down I couldn't pay I already paid for over 38 months which I already paid 72000rand already .. I continued paying for 5 months ... so my question is for a 67000 loan why is my interest over 100% because the loan all in all 172800rand is that possible ? I am so angry at this bank wooow