Spice Jet Airlines — Rescheduling of flight

Hi
i have booked ticket for my wife and kids for 23 march from pune to jammu.
when i booked the ticket i kept in min layover time and accordingly i booked it
subsequently i have been told that my flight is rescheduled and the layover has been increased to 18 hours
this is morally wrong
if it was rescheduled it should have been done keeoping the mi layover now my family has to spend 18 hours on airport
i booked the ticket so that they spend min time, iwould have boked in othe rflights which were cheap and had lesser layover
this is ethically wrong and i request u to [lease refund my money
thanks