How to save it I'm not sure, I haven't used a kit, as I have my own cider apple trees. I assume in a kit form everything is in balance? I have to make sure I have an sg of 1050 or better or I won't make enough ethanol for the cider to self preserve as it ages. I also have to make sure I have enough malic acid to prevent an excess of acetaldehyde from forming and spoiling the cider. I correct this by adding extra Bramley juice to adjust the mix.
It appears the aerobic fermentation may have stuck after the anaerobic fermentation should have started.
This could happen if there was a hang up of a cleaning agent, how did you sterilise your equipment? Cleanliness is more important than sterilisation, in the aerobic stage there is enough energy for the yeast to feed on the sugars, in the latter stage any chemical residue may stop or slow it. Fermentation process will kill most viruses but not bacteria, some good bacteria are welcome, but sterilisation may kill the good bacteria as well. I eyeball everything is spotlessly clean, and rinse well with hot water.
Try as mentioned a basic starter, dissolve a sugar water mixture in a demijohn add in some yeast and say, Youngs yeast nutrient wait for the fermentation to get vigorous and then pitch in to you juice and see what happens.
if that doesn't work just set it aside somewhere cool and dark over the winter and check again in the spring.