DISCLAIMER:
Between edits and comments, the original question has morphed from being about cash-back, to cash-equivalent store credit, to voucher for a percentage off the next purchase, to an actual "gift". These are all distinctly different things! And as of this writing the "question" doesn't actually ask a question. ("I am arguing that...")
Also, taking an order, "unilaterally cancelling it" and then offering only a partial refund is completely different than taking an order in good faith, having a third party fail to deliver and offering a refund for the portion that didn't deliver when the consumer refuses to return the other part of the order.
There is no answerable legal question in the current iteration, and not enough information given to determine whether the merchant's actions rose to the level of illegal false advertising. I am tempted to delete my answer, but in the interest of posterity, for educational purposes, and at risk of being deemed TLDR, I will leave as-is for now...
This is less a legal question than a math problem, marketing tactic, and business accounting practice to understand. Consider the following examples:
EXAMPLE #1: (mirrors the situation described in the original question)
- An item is advertised for sale at a price of $100, which includes $30 "store credit" (voucher, gift card, etc.)
- You spend $100 and the item is placed on order, plus you receive a $30 credit.
- Your net, or actual out of pocket cost, for the item is $70.
- You can hold on to the credit until it expires, or use it to purchase something. In any case, you are in possession of $30 of "value".
If the item fails to deliver, you are only owed the net value of what you spent for the item, i.e. $70. You are not owed a refund of the $30 because there is nothing to refund - you still have a $30 credit, or whatever thing of value you traded it for. The credit was not lost in the parcel with the other item, if the company pays you $70 for the lost item you will have been made whole again.
If they paid you an additional $30 you would be unjustly enriched beyond what you originally paid because you still have either a $30 credit, or the thing of value you traded it for. That was a separate and new transaction. If you would like a refund of that item you would need to return it and negotiate this separately from any reimbursement for the value of the package that was lost.
Cash back, store credits, gift cards, vouchers, etc. are all just silly marketing tricks. To drive that point home let's consider the same example, but with a slight twist:
EXAMPLE #2:
- An item is advertised for sale at a price of $100, except... this time it has a special sale tag marking of 30% off.
- The discount is applied, you spend $70, and the item is placed on order.
- Your net, or actual out of pocket cost, for the item is $70.
If the item was lost it is reasonable to expect the merchant to refund you the sale price you actually paid, ($70) not the regular price, ($100).
The only practical difference in these examples is that in the second one you kept the $30 in your pocket instead of handing it to them, only to have them hand you a gift card right back. Whatever insurance the company has with the courier is irrelevant to your purchase agreement with them. They are not obligated, and you have no leverage to demand any portion in excess of what you paid for the item.
At the risk of beating a dead horse, let's consider one more that more closely mirrors the first example: (except it's a return vs loss, just to add some interest and show that the cause of the refund is irrelevant)
EXAMPLE #3:
- An item is advertised for sale at a price of $70.
- You go to the register to pay for it, and decide to also grab a $30 gift card.
- Later you decide to return the item, but want to keep the gift card.
You paid a total of $100, but the company would only refund you $70 for the item you returned. Since you still have the gift card you are not due a refund for it. It always works this way if you return a single item that was purchased along with other things not being returned.
When you buy something for $100 and receive the thing plus $30, (cash, credit, whatever...) you execute a transaction functionally equivalent to examples 2 & 3.
Again, it's all a marketing ploy because surveys show that people will buy more when something extra is advertised as being included for "free". But it isn't free; nothing is. The business has already placed a value of $70 on the item, inflated the price to $100, and included a "free" $30 credit that you paid an extra... $30 for.
In terms of accounting it is all just gross revenue.
