the interst charge is scary and rediculars

I'm in areas with African bank and I'm paying towards the areas, as it was agreed that when I pay towards the areas my areas amount will not increase to my surprise today when I log on I'm sitting on 45000 and last week it was 40175 how possible is that , will I ever finish those areas ? Please stop cheating me and what you have told me is different I'm trying to reduce them but you keep on adding.