Personally when a girl said,
"I was waited for your reply" or asked,
"Why didn't you call me last night?" to a guy;
They didn't expect a sorry note from the guy. They just want you to know that they're thinking about you. They just need perhaps 10% of your attention in 24 hrs time if not 100%. A woman didn't ask 100% concentration for them. Enough to show them some care, enough with simple conversation to give them comfort.
A simple, "how's your day today?" or
"how's your meeting just now?" is more than enough.
A little note, may looks stupid for you. But for a woman, is a huge quick relief when they received. It just brighten their days.
They don't ask you to pamper them.
They don't want your money.
They don't need your 24/7 attention.
They just need a little care.
They just want to be loved.
and most importantly,
They love you, and thinking about you all the time.