Building loan finance

This store is robbing me, I have been paying them but they always says I am on areas with 6000, I only took 12 000 but I have been paying them since 2022 and I pay double of what I suppose to pay. I am pretty sure that their money and their interest is fully paid but they still says I am owing 7000.i will never take anything from them again in my life. They are ****** yerrr. I want them to reduce this interest