Asos fail

I am really rather angry.

Asos.com has been, up til now, my favourite online shop. I just finished making a very sizeable order and, after i had put in my payment details was told that there had been a problem and my order had not gone through. So i went and made a duplicate order which went through with no problems. Then i checked my email and found i had 2 order confimations and that the first order i had made had gone through after all. So i emailed their care place and asked for my second order to be cancelled.
I have just been told that they cannot cancel orders once they have been submitted because: 'our warehouse picks, packs and processes your order fully within 30 minutes of you clicking the final confirmation. Your order then gets put with thousands of others and it is impossible for us to locate a single parcel amongst the rest'

However i reported the problem and asked for them to cancel my second order within less than 5 minutes of making it!

It is absolutely rediculous that they cannot cancel an order, especially as the reason i made the second order was due to a fault on their website!
So now i will be delivered 2 parcels and have to return the contents of one. My disability means that going to the post office is highly traumatic for me and so i avoid it at all costs. So having to return a parcel is stressful anyway, without the added frustration that it's not my fault. 

Also, like i said, this was a large and pricey order. I checked before i made it that i could afford it, but not twice! And it will take a while after i've returned the duplicate parcel for my refund to get processed. So basically they have put me in a financial mess.

Asos are a great site, and their sale (which is what i bought from) is amazing. But being unable to cancel an order made less than 5 minutes before i reported the need to cancel it is just terrible. I've had annoyances with their customer service before. Namely that twice i bought a specific type of ring and twice these rings arrived broken, in the same way. On their refund slip that comes with your order it says something along the lines that if anything arrives faulty and you report it they will ship you out a replacement immediately and give you 10% off your next order. So the second time this happened i decided to report it. I also tried to help out, suggesting that the reason the two rings had been broken was due to them being wrapped only in a plastic film and that the replacement i got for the first ring had come in a box, which seemed better protection. My reply basically just said 'just return it as usual'. So not only did i not get the 10% off that it mentions, but they completely disregarded my attempts to be helpful to them, which i really did not need to do after their merchandise kept breaking before i even recieved them.

LILLIAN SMASH!!

Edit:
After i complained about this on twitter Asos care got in touch with me and have offered that, as soon as i have a dispatch number and tell them they will get the... deliverer to return it to them, and then refund me as soon as it returns to them, which obviously would be a lot sooner than i i had to wait for it to be delivered and then return it myself. This is good. However i still think it's silly that they couldn't just cancel my order so soon after i had made it. Also if i hadn't been on twitter i wouldn't have got this option, which doesn't seem fair.