Re condition the pair. Just because it didn't work the first time doesn't mean they'll "never spawn". This is their first time - there is a chance they could get the hang of it the second time around.
What gets my pairs to breed? I'll tell you what I do:
Currently my breeders are being conditioned. They are being fed 4-6 smaller meals of a variety diet: meat of mealworms (head chopped off meat pulled out by the fish), New Life Spectrum 0.5mm pellets, frozen bloodworms, frozen mysis... I exercise them (a male or a mirror) once every couple days. Their water is cleaned once a day. Their temp is never below 80.
Then when I am ready to spawn them, the male is in the spawn tank for at least 24 hours before introducing the female. At this time I still offer the variety diet and clean the water once a day. I bring the water height down to 4 inches. I usually make sure to use live plants, and one "cave". I flare him a couple times, and have the temp at 82. Then the female is placed in a breeder's net or a floating cup. If the male only attacks the cup and doesn't "lead away" from her, preferably towards his nest, I don't let her go. Overnight if he shows the right behavior, I release her. If he doesn't, I introduce some of her water to his (only used if fkoating a cup, as the net allows the pheremones to slip through) or I flare him with the mirror, pretending to be a "rival". ****I also use clingwrap ontop of the tank keeping it absolutely humid in there. I may also "mist" with a spray bottle of water, mimicking rain. I offer food three timee a day to both of them when they are together. Then when they want to spawn they stop eating :)