Sorry to hear you've had such a rough time with the slot machine, especially after spending over 500 Quartz without hitting the jackpot.
There's actually a mechanic built in where the jackpot chance increases the more times you spin in a single session (as long as you haven't hit a jackpot yet). So it's better to do a bunch of spins in one go rather than spreading them out across multiple play sessions. Usually it takes about 150-200+ spins to land a jackpot for the first time. Hope this helps!