Disallowing to increase debit installment

I called RCS twice with a request to increase my debit order installment. <br> <br> I was given an email address of [Email Removed] by the first call center agent for my request however the email bounced.<br> <br> I then decided to call RCS back however the second called informed that it is not possible and i have to do it manually after the debit order is completed? what an inconvenience!!!!<br> <br> I want to setup a debit order of a fixed R1000 over the next couple of month so that I pay up my account in full.<br> <br> Please assist with clarity as there seem to be confusion.