hi,
you can try to disable status transition from CNCL to CL, if this will not work you can try to enable that transition and define custom Condition that will be always false and prevent status chaning on any situation. (simply set_return_data(FALSE);).
But, my personal opinion that you shouldn't manually interact with CA Spectrum tickets using CA SDM and should let them live their own lives from Spectrum side.
Regards,
Timur Alimov.