Suppliers usually have their stock up to date, but in case it's not, suppliers may suggest an amendment, whether it's a modification, reduction or even a cancellation in case all items are unavailable.
Reductions or item changes are always subject to your approval.
If you have paid upfront a refund is done automatically. Please note it can take between 3-5 days for the money to show on your account.
If you have trade credit, your credit amount will be updated automatically.