You can claim VAT in store (includes online orders) for purchases made in excess of a certain amount, for Belgium its 125,01 € and for the Netherlands its 50,00 € so long you are a non-EU national and leave the EU within 30 days. You can do this in store by speaking with a member of staff or online by creating a tax free form.
For online orders, you will need to have your tax invoice present along with the items purchased in order to have your claim processed.
