Homechoice stuff account

in 2015 I was called by this MBD attorney's collection agents, regarding my home choice stuff account, and this gentleman adviced me to make arrangements to pay back as I had informed him I am un employed, and was informed I have to pay 4000 and something, I started paying R150 into their account I was sent and sometimes R100, then I was told that if I pay into the account there's charges than when they deduct in my account and I rather promised them that I will make sure that the account has at least R100 that they can deduct... I then played this from 2016 till 2017, because I thought I should almost be done paying I called 2018 in September and the lady told me I owe 1200 which I then would be finishing off in August...

On Friday I called and I was told that I owe R1650, I enquired how as this guy explained that the initial amount I was supposed to pay was 4010... of which I believed that it included interests as the basic salary I recieved then at home choice was R3500 and per agreement it's what you would pay back if you did not work your notice.

So what I do not understand is how then do still owe R1600 when I have payed R3850 from theR 4010 we had agreed on when they had approached me. What's funny is I am told of interests which I was never told off that accumulate every month.

If this is how this works then MBD is making money out of people.

Today I called and I was told the system is slow and will be called back, guess what no one called me and no one can explain to me how then is the money increasing instead of decreasing