Further info: Following my annoyance at Cambrian Wharf being shut yesterday, I got an email from them this first thing this morning saying they don't even stock the cards. So changed my plans again and went for the option of buying a 25 unit pump-out card from Limekiln. In spite of what Alway Swilby has said, it didn't work in either slot. It was the last pump out card at the chandlers so the possible reasons would be: the card is faulty; the bollard is faulty; Alway Swilby is wrong; the bollard has been changed in some way. I then wrote an annoyed email to various senior people at CRT, detailing another, all too familiar tale of CRT cock ups. Finally, about half an hour ago, I got another email from CRT saying they do stock the cards at Cambrian. But I'm now a broken man. I'm not returning to Birmingham for the third day running if there's any chance that the bollard is faulty. I just don't think I could take any more disappointment. So I'll be unnecessarily polluting the area around the basin for the next few days. Sorry folks. I'll let you know if you I get any reply from Julie Sharman etc.
Did you try lifting off the last railing? It always used to be removable.