Has it been mentioned in the Holy Quran or the pure Sunnah that there is a specific supplication or recitation of verses to lift oppression when it occurs, especially if other means of redress have proven ineffective?

Asking Allah is a great act of worship, and Allah has promised to respond, as He says: "And when My servants ask you, [O Muhammad], concerning Me - indeed I am near. I respond to the invocation of the supplicant when he invokes Me," and "And your Lord says, 'Call upon Me; I will respond to you.'" Therefore, whoever has been wronged should turn to Allah in supplication to have that injustice removed, and they should choose what suits their situation. There are no specific supplications in the Quran and Sunnah for removing injustice, but the supplication for distress is: "There is no deity except You; exalted are You. Indeed, I have been of the wrongdoers."