Being randomly chosen as a selectee in the visa lottery does not guarantee that you will receive an immigrant visa. Selection merely means that you are eligible to apply for a diversity visa, and if your rank number becomes eligible for final processing, potentially you will be issued a diversity visa. However, in order to receive a diversity visa to immigrate to the US, your application still must meet all eligibility requirements under US law. These requirements may significantly increase the level of scrutiny required and time necessary for processing. Unless you have actually obtained your permanent residency, you should not abandon your EB-5 immigrant project.
Secondly, whether you can withdraw your investment from the EB-5 project depends upon the agreement you entered with the regional center. However, if you have already filed your I-526 with the USCIS, you have committed the investment funds and put them at risk in the investment enterprise.At that point in the EB5 process, you have no legal recourse to have your investment refunded.