Since September I have made several orders every 2 weeks with the colleague discount applied. The discount is applied not when you place the online order, but when it arrives from the store to you and will be shown on the receipt it comes with. I have used my colleague discount for several online orders since September but it has been applied to none of them. The first time it happened I contacted customer service by email with that and another problem with the order, they ignored the problem with the colleague discount and instead only addressed the other problem with my order.
I decided to contact customer service again specifically about this, and they have redirected me to HR, telling me there must be some problem with my card. HR then redirected me to customer service. So I told customer service that HR told me there's nothing they can do, there shouldn't be any problem with my card if it has been successfully linked to my account. Customer service then gave me a voucher for my most recent order and wrote "Thanks for responding to our email. I'm afraid we would only be able to apply the discount for the last order as this is the first we've been notified regarding the issue."
So they've acknowledged their error in failing to apply the colleague discount to all of my previous orders, but don't want to do anything about it because "this is the first we've been notified". I don't get how it being the first order they were notified of with this mistake should prevent them from doing anything about the past orders. What relevance does a successive order have on the problems of the last? Why is that important? It doesn't make sense. It seems to me they've just made up some arbitrary rule so they don't have to correct their mistake. You can't overcharge someone and play the "too late" card, that's not how consumer rights work, especially when those orders were placed in the last weeks/months not years.
As mentioned earlier, I did contact them the first time it happened and they did nothing about it, I will forward them that mail. But I have a feeling they'll mess me about even more by inventing another arbitrary rule like "we'll only compensate you for each time you contacted us about a problem before you placed a new order" just so they don't have to do anything about the rest of the orders.
The scummyness is bewildering, wherever they could fob me off they did. How do I best articulate/put into words a response that presents how unreasonable and unfair they're being and holds them to account in such a way that they have to correct their mistake and issue a refund for the overcharge on all the orders?