Firstly have a look on your invoice and if it is under shorted products? If it is, then the product is out of stock and normally you should receive it in your next order, if not you can phone head office (0860102345) and ask them when the product is expected to be back in stock again, or email them (email@example.com).
Kindly explain to your customers that all offers are "While stocks last". You will only be invoiced after the product is added to your next order.
If the product is on your invoice but not in your box, mark the missing product on your invoice and send the invoice to me, I will then forward a credit slip so the amount will be credited back to your account. Arrangements will be made so thet the product will be included in your next order, if in stock.
This can take 2 to 3 weeks.