After delivery, customer reject or cancel e-invoices in MyInvois Portal, do we need to response?

Any rejection and cancelation request sent by the Buyer is subject to the acceptance of the Supplier. Harrisons will not accept any “Rejection or Cancelation Request” from the e-Invois Portal. However, Harrisons will still entertain any complaint from Customers pertaining to any issue on pricing, promotion, or errors through normal channels (i.e., through the Salesman, Warehouse, or Accounts Department).