Glucore carries a 60-day money-back guarantee from the date of purchase.
The guarantee runs for 60 days from purchase and covers dissatisfaction with your results or your overall experience. That window comfortably covers the 4 to 8 weeks nutritional support of this kind typically needs to show an effect.
Contact the official store directly with your order number, within the 60-day window. Some guarantee programmes require unused or empty bottles to be returned; confirm what applies to your order before shipping anything back.