False Advertising and ********* Business Ethics

I bought A Duvet Inner "Simon Baker- Hungarian Goose Down Duvet Inners 90% down/10% feathers from OneDayOnly. However the Duvet was shedding feathers as if it was 100% feathers. I sent Onedayonly an immense number of images as well as a video depicting the state the Duvet inner was and the total mess it was making on my duvet covers, sheets, clothes and room. I purchased it 6 months ago and have only been using it for 3 months. They asked me if I washed it and I told them NO. Obviously nobody washes a brand new Duvet inner! I've only used it for 3 months, what's the need to wash? So anyway, they collect it and send it to the supplier. Few days later they send me an email telling me the supplier said I washed it and used fabric softener so they cannot refund me, they sending they Duvet back. They still haven’t given me an explanation as to why a Duvet that supposed to consist of only 10% FEATHERS is shedding feathers as if it’s 100% feathers. If it doesn’t have 100% feathers, why is it still shedding feathers? Surely if it had only 10% feathers by now the 10% is out from the Duvet so it shouldn’t be still shedding because the balance of 90% should be down! WHERES THE EXPLANATION ON THIS??? I find their behaviour totally revolting and utterly *********. To make a pathetic excuse such as this just to get out of refunding a customer for a product that is totally against the description stated on the website is not acceptable. Furthermore, if they insist it was indeed washed with “fabric softener”, then I have to insist that they sold me a second hand/ used Duvet because clearly, I didn’t wash it! If I didn’t wash it, and they say it’s washed it means they sold me a used product! Now Onedayonly can claim all they want that this is what the supplier says, however, I purchased the product from Onedayonly, not their supplier. It is their responsibility to ensure that the customer gets exactly what they paid for. If the product does not meet the requirements of the item as advertised at the time of purchase, then surely they should refund you in full. A customer has the right to get what they paid for, not false advertising products! If you sell a defective or used item to a customer, you need to refund them, not make excuses and try to blame the customer!!! OneDayOnly, I want my refund in full!!!