Capitec bank

I am beyond frustrated with Capitec bank because they have became a very notorious bank lately.They had a glitch on their system and error occurred while I was transferring money to people from my banking app,on my end the payments went through but apparently,the funds remained in my bank account.Once they picked up the error I a -R 1 556 on my savings account.I liaised with their complaints department and we made arrangements to pay R 250 on a monthly basis for six months.However,they are deducting 3 payments simultaneously on the same month.Their customer service is **** and not really beneficial and I don't know why they have one.I want them to reimburse my money or I will take litigation against them.