Once your 30-day Money Back Guarantee has expired, you will have the opportunity to upgrade your diamond at any time in the next five years. There is no restocking fee for this service and you can upgrade as many times as you wish. To upgrade your diamond, send it back to us with the original certificate and you will receive credit for the full price you paid. For example, if you purchased a $3,500 diamond and want to upgrade to a $5,500 diamond, you can return your first diamond and pay only $2,000 for the upgrade. If your diamond incurred any damage OnDiamonds.com will accept the diamond back, but deduct the cost of polishing and reshaping.