Investments usually are not guaranteed, kind of like of playing stocks, you win some, you lose some. You need to review your agreement and check in with your state's securities department or the U.S. Securities and Exchange Commission to find out if this contract was or should be regulated by them and if you need to file a complaint through those agencies. Next, if you can, consider speaking to an attorney who can then try to determine if your agreement and the guarantee provision were legally binding and enforceable. If so, then a lawsuit may be your route if those two agencies do not have sole authority to obtain reimbursement for you.