I am also an victim of barclays poor response & unethical approach. Presently they have been chasing me sign up for the "Priority Circle" scheme. Under this scheme they are offer a lot of stuff, obviously subject to certain "terms & conditions".
I have refused to sign up for same at least three times, however this bank keep on constantly following and repeating same thing every time.
Further they are extremely rigid in their approach. Firstly getting thru their numbers is very difficult, and even If you manage to get them, no guarentee you will get solution of correction of your issue immediately. They take at least 6-7 days to respond, plus its you who has to follow up for the response.
Funny thing is for my 28 paisa outstanding they informed me to pay up interest of Rs 250/- when asked about explaination, no reply from their end.
Therefore I have decided not you use their credit card anymore. And also would like to advice all MS users not to get associated with such a useless bank at all.