overdue interest charge even though full instalment was paid

I did not check it before but now I look twice when I received my statements.

On 11/05/2019 I Received my statement to pay my instalment of R3441.50 on vehicle and on the 24 May I paid R3500 before the 27/05/2019 as shown on the May statement.

This morning I received my June statement that my account is R348.50 in arrears What I don’t understand why the arrears if my due payment was made on time ? Could some from their vehicle finance department just explain if for me.

I had send several mails this morning with no feedback ? And on my June statement it show payment received on 24 -05-2019..So why the arrears .

Please Explain that for me