Debit order/Payment Options

I called in on the 16th of September 2015 time 13:25 with regards to a request to increase my debit order as I am planning to pay of my debt with RCS. The consultant I spoke to informed me that she was unable to change the amount, that it is system generated and that I should rather go in store and pay the extra amount before or after the debit order. The reason I pay via debit order is to avoid going in store to make payment? Why is it not possible to increase my debit order amount?... When I asked for her name and a call reference she decided to put my call on hold instead of providing me with her name and the call reference. Your call centre staff is very unprofessional and don't seem clued up