Decrease of loan instalment

I took a loan with Capitec bank i payed for 4 months on the 3rd month i realized that my responsibilities have increased .i then called the bank i was told that i should wait for 6 months at first ,i went again to the branch i was told that i i must wait for 4 months which was finishing on the 4th of December 2017 today on the 15th i went again i was told that they cant help me i must produce a proof which i didn't have i told them that its a family responsibility how can i produce proof for that .i then told them that i am coming to them because i do not want to end up changing my account and not pay them i want to pay but smaller amount .still they refused to help me.please help me i want to continue paying them but but at least 3000 per month