If it's a systemwide error on EAs side, a change can be done as a systemwide correction - this isn't really a reversal of an SBC though, the way you want it. It's not possible to reverse an individual player's SBC. Once again, please refer to the article, where the details and limitations of SBCs are explained. Here is the part I'm referring to:
All SBC submissions are final. Once you complete an SBC, the Items you submit are permanently removed from your Club in exchange for rewards. Our advisors can’t restore Items you’ve submitted.
Once again, unfortunately, there is nothing to be done in this situation.
Please make sure you check thoroughly before sending off an SBC as they are final.