SA Homeloans increases my monthly repayment every 3months!!!!!!

SA Homeloans has been increasing my debit amount every 3 months!!!!! when i took out my loan it was R8107 in Sept 2021 a year later my debit amount is R9510,05 how the hell do they expect you to pay over a R1000 extra in 1 year!!! what will happen after 10 years!!!!!