These holding letters are standard practice for Barclaycard. They refuse to buckle down, even the threat of legal action doesn't bother them. They are a disgrace, it seems from my encounters with them that there is no communication at all between departments or people in the sam department.
They even stick two fingers up at the regulators. As you are probably aware if people make a complaint under the data protection legislation or face the consequences from the government body in charge. From what I have heard every other organisation manages to do this, but Barclays are apparently too busy to be able to.
The sooner this scum is put out of business the better for everyone, they are an insult to the bad name of banking.