Hello IainJ,

I know how it feels when you've used up too much time waiting. I can send feedback to our managers regarding your recent experience with our phone support.

Currently, we have an open ticket about this error. Rest assured someone from our workforce team will send updates about this.

Meanwhile, you can upload bank transactions into QuickBooks as a workaround. Please use this handy article for the detailed steps: Manually upload transactions into QuickBooks Online. 

I've also added our page about banking for some helpful articles for your future tasks.

Reach out to me anytime if you have other questions.