Hi @ Kleiner,
Firstly I was not having a go at you or your issue with the seller. I was informing all that for me I understood their terms and condition and purchased accordingly. Your situation at the time no way reflected my situation when purchasing. If there is a issue further down the line with this supplier and I am not happy with the outcome, I will decide whether I will continue to purchase from them going forward or not.
As @sixgun has shown is appears their website has been updated since before I started to give a better understanding of terms and conditions going forward. This was likely down to you raising your issue.
I do agree with you on your third point
:Thirdly, when they cancelled the order they did not mention any consequences that would be for me. - You should have been notified upon order cancellation of pending fees and your goods should not have been held to ransom.
I know your current situation is extremely frustrating for you and thank you for sharing your experiences with us. I have been in a similar situation many times over my life and have come to the conclusion based upon all the time and effort that I put into trying to resolve the issue, cost more in time, frustration and money. Believe me you will come across worst situations than this and it will be all legal.
Don't let this drag you down any further and look at your long term goals with regard to your stacking.
Keep the faith.