Kamoer Dosing Pumps - Help / Question

[TheZoalander]

Need a bit of help with setting this unit up. Read the instructions, seems straight forward from a programing standpoint. For whatever reason I'm unable to program more than pump 1. When I get to the screen that says what pump I'm on with the "1" highlighted, I would assume I can press on the up / down arrows and it would change pumps. Could someone shed some light on this issue, before I throw it out the window Thanks