Question Author
Spheric, I appreciate your advice!
I am starting a procedure with my credit card company.
They say they will research the problem and let the publisher refund my money as long as the research is completed within 120 days from the date of purchase.
In my case only thirty days are left, so there is a possibility that they will terminate the research, which means the refund is not secured.
But thank you anyway.
My aim of the submission of the question is being fulfilled.
But here is another aim as well. I wanted everyone to know there is a dishonest publisher in Wales (I have an urge to reveal the name but I'm keeping it down)
According to their site, it is "Wales's largest independent publisher". Indeed their name is found in many books in Welsh, but their customer service skills are so rude and poor as to discourage a foreign student from learning Welsh and leave him a bad impression of Wales!