Is legal action for bad employee treatment the best way to get through to Instacart management?

I am struggling with an employment issue regarding Instacart, the online shopping app. Due to errors their system, my earning potential was dropped by 60% for reasons beyond my control, and thigh I have all the proof that I need to clear my name according to their policies, they have done nothing six months later on. I took a low-paying second job to supplement my income from Instacart, assuming that their reconciliations for the problem would be quick, but due to their failure to resolve issues, I have lost significant pay opportunities.

I made attempts to contact Instacart and get this resolved. However, I was not capable of contacting Instacart management as the only options that I have to speak to Instacart was via their "Shopper Support" which is incapable of doing much more than repeating the information posted on their website. They have also regularly sent me to email non-active email addresses and claimed that the company would contact me within 48 hours to resolve the issue on at least three occasions, all of which have been false. Is there a method besides legal action that I can take to contact the management and get this resolved for good?

I have more details if necessary. Thanks, Luke