There are many reasons in commercial life why a complaint might be necessary.
1.The wrong goods may have been sent.
2.The goods might have been damaged, sent late, or not delivered at all. Or your company might keep receiving consignments for another firm with a similar name, address, or account number.
3.The supplier may have overcharged you.
4.A service, such as a repair, might not have been carried out properly, so that the engineers have to keep returning to fix the same machine.
5.A customer might not pay his account on time and not reply to further ‘request’ for payment.