CVEC is due by all degree-seeking students enrolled in higher education institutions in France meaning that students enrolled on the Rabat or Singapore campus are exempted (if they also pay their tuition fees in Rabat or Singapore).
If you have unduly paid for your CVEC it is possible to claim reimbursement on the same website where you bought it but you will have to provide a European bank account reference:
It is also possible to claim reimbursement if you have applied for a deferral which has been granted.