INCORRECT REFUND

I settled my Direct axis loan on 12th December 2023. The full amount was settled and the account reflected as zero with a few hundred over to be refunded. I got a call from them informing that I was due for a refund. On 14th December 2023 the normal debit order ran (which should NOT have come off as the account was settled). But I ignored that and expected it to be refunded as it was just 2 days apart from the day I settled. I sent them proof of payment of the settlement on the 20th December 2023 as they requested in order to receive my refund. On 25th December 2023 the account reflected interest charges, credit life insurance and service charges. This is after the account had been settled on the 12th. I received a refund today (03rd January 2024) which is short of what I should have received because Direct Axis charged me interest, credit life insurance and service charges on a loan I HAD ALREADY SETTLED. I WANT MY MONEY BACK. I settled my FNB loan which debits me on the same day and charges interest on the same day but they gave me my refund correctly without charging me for a things I should have NOT BEEN charged for. What makes me more angry is that my refund is even less than what the debit order amount was. HOW????????