RAMPS PLUS 2 and E1 socket problem (K200 Delta, but related to the PCB , not printer)
Repetier reads configuration from the printer when a connection is established, so as long as it gets info about 2 heads it will display it.

The best approach will be to disable heatbed or hotend directly in the firmware and reflash the printer. You could also swap pins on the board.

When you decide to reflash the firmware, you could check with producer if they have suitable one or use Marlin (this is a configuration guide).