Yes, 100% the issue of new sellers understanding the differences between account types and selling plans - but to be honest, I feel the fault lies with the initial sign-up/registration process, as too many new sellers simply click on the big orange ‘Sign Up’ button, and then wonder why they have been charged £30 for the Pro. plan., and there is not really clear explanation of the differences, especially with the dual use of the name ‘Individual’ for two different things - but you know this as has been mentioned SO many times before, and the suggestion made to change at least one of them.
Someone a while ago suggested that the sign-up process should be in the form of a flow-chart so that new sellers take the correct ‘route’ to the type of account they need - it would save a huge amount of problems and stress.

Also agree with the issue of A-Z claims - especially those being opened by CS on behalf of the customer, without the knowledge of the seller, and without the customer contacting the seller first.