By one wake up call, I meant only one call can be set up.
My example: Saturday night, DH wants a wake up call for Sunday, 3:00 a.m.
I called the front desk because I wanted a second, 6:30 a.m., wake up call on Sunday morning.
In order to have a second wake up call for the same morning, the front desk had to manually call me themselves. Their system would not accept two wake up calls set the same night for the following morning.
I was surprised that after setting up the wake up call, a second wake up call could not be added. Or for that matter, no option was provided to cancel the first one.
Seems to be a very basic system.