Frustrating Online Payment

You had a flash sale on your bolia couches which ran from 23 - 25 March 2018. I placed an order on your online portal and have been having issues with trying to make payment due to technical issues between you (the merchant) and my bank. I have been on the phone with my bank and yourselves from yesterday trying to sort this out but it seems no one is willing to take accountability and resolve this issue. Called in yesterday and the consultant that assisted me was very helpful but advised me that her hands were tied because your technical team was saying they could not pick up any issues, whilst my bank is also telling me that the issue is on the merchant's side (apparently they have no record of the transaction on their side). The couches have been reserved for me for 48 hours (since Saturday) and now, I am going to miss out on this discounted price due to an error I have nothing to do with.

The consultant that assisted me suggested I use another card, but I do not have another card to pay with aside from my American express card, which you do not accept. Further to this I even offered to go and pay for the items at one of your stores, however your consultant told me that this is not possible. I offered to pay via EFT, again I was told this was not possible as I had originally selected card as my method of payment - WHY DOES YOUR SYSTEM NOT ALLOW FOR CHANGES TO PAYMENT METHOD?

I have never been so frustrated! I want to pay for these couches.... HELP ME.