How about making complaints to Barclays, rather than TFL. I’m sure a quick google would find their PR peeps numbers…
Personally, I would never bank with Barclays, but if I was inclined to, the shambles of the systems would put me off.
Why would Barclays have any say in this? They just pay money to TfL to have their logo’s on the bikes and terminals. they dont run any part of the scheme that falls to TfL and Serco.