On your resume, indicate why you left each job -- not just these two, of course. Make each explanation brief and true:
- Resigned due to family member’s health crisis requiring my attention.
- Resigned to help my mother with affairs resulting from the death of my dad.
- Employment situation was rendered untenable due to employer’s change in circumstances (or whatever you want to say caused the employer to renege on his/her word to you. Just do not make the employer out to be totally disreputable in the process if you can help it.)
- This job didn't turn out to be as described or promised. Very disappointing.
When you are interviewed, be matter-of-fact and brief about each situation. Honesty is best but do not belabor either situation. Instead, spend time pointing out your great work record at prior jobs showing your loyalty and steadfast behavior.