Bad service - no one seems to know and being sent from pillar to post

I have made arrangements with Fin choice to pay R500 a month and which i did this month. as I'm no longer employed. I asked my mom to assist with monthly payments and she requires something written that i have made arrangements and i will pay R 500 a month on my mobi money. when i called I'm sent from pillar to post no one seems to want to help or know and I'm told they cant. so I told them then i wont be able to pay if the don't give me something written down. I don't know what is happening as this doesn't make business sense when i try rather to default. can someone assist me urgently.