So I had this same issue where the website was incorrectly charging £120 GST for an award on Qatar. Called and spoke with EC and faced a very rude operator. He refused to double check with the fares department and was stubborn that the taxes displayed on BA.com are always right. I politely asked him again and again to double check with the fares department and when he finally agreed before putting me on hold he called me a "a**hole" He obviously said that before putting the mic on mute.

I questioned him that he should not have called me that which he blatantly refused. (do they record the calls?) He finally checked with his manager who also agreed that the taxes were correct and said there would be no point in sending it to the fares department. I politely requested that he does that which they finally agreed.

Will update when I hear back.

On a side note what would others do about being called a "A**hole" when you are trying your best to be as polite as possible.