Find a reliable gold website like RSorder for a way to be sure that you'll receive your RS Gold. Since they're a highly experienced website that has been trading since 1999 and knows the industry inside and out, they are able to protect trades.
They have a number of great security measures in place to stop fraud. They also have an escrow service that's modeled on PlayerGuardian to ensure that the Old School RuneScape Gold that they sell on their website will be delivered to purchasers.