Worst loan company

I will not recommend this company to loan from. I phoned the 29 Jan 2019 to settle this loan, I specific asked for the full amount and they give it to me on the phone, the same day I paid it in full, I thought it was settled. On the 11 Feb 2019 I got the statement from RCS and this is how show on the statement balance R6119.86 credit debit order25 Jan 2019 - R676.49 balance R5443.37 I phoned the 29 Jan 2019 got settlement amount R5575.44 the balance is now minus (R132.07) so RCS must pay me back this amount, but no they go and charge on the 10 Feb 2019 INTEREST of R105.68 and when I phone them they was so rude on the phone and say the interest was not worked out for Jan 2019 and therefore they must still charge me interest, I told them, but you gave me a settlement amount how can you still charge me interest. They are the worst people to loan from, think before you use them.