Capfin is not transparent with their customers, bad business practice

I took a loan of R8000 for a period of six months on the 2nd of October 2019, my first instalment of R1,814.23 went off on the 25th of October 2019, the second one in the 25th of November 2019 and in December did not pay but I made an arrangement to pay the arrears over two months together with the loan instalment of R1,814.23. In January 2020 I paid the arrears amount of R907. 11 together with my monthly instalment of R1,814.23 and in February 2020 I paid again the arrears amount of R907.11 together with my instalment of R1,814.23 and in March 2020 I paid my last instalment R1,814.23 of the loan as per the contract, but I was so surprised, disappointed and furious on the 25th of April 2020 when they debited my account for the amount of R1,814.23 whereas my loan agreement was from October 2019 to March 2020 I reversed the debit order because it did not make sense that I entered into a six month contract for a loan and honour all my payments then the next thing they deduct againI , I sent them an e-mail on 29th April 2020 which they never responded to and I contacted them on Monday the 04th of May 2020 to ask them why, and the consultant told me that there was an interest which I was charged for the month of December 2019 BUT my questions are as follows 1. Why did they not debit the interest on the 25th of March 2020 since that was my last instalment? 2. Why keep quite all this time and never communicated anything to me? 3. Why wait for the 25th of April 2020 way after my contract term with them has ended and deduct an amount of R1,814.23? So I asked for the statement from the consultant to know how much is that interest that Im owing but never received the statement. I then logged in on Capfin online to check, the statement online shows that i still owe the R1,814.23 instalment plus the R220.36 How did they arrive to the amount? Why must I pay a six month loan over the period of seven months? They have inconvenience me a lot the previous month it was a clear **************** and a very bad business practice. I will never, ever require their services anymore Regards