I know these are difficult times, but it would be very useful if there was a way to email simple queries (like why my overcharge hasn't been removed as agreed) rather than hanging on the phone for an hour. It doesn't need an immediate action from you so you could answer in slow time (leaving your staff available for those who do need them now) and would be more efficient for us both. You could ask for a private message and/or phone back and/or Chat or some secure way through the PlusNet account site for any personal details.
Please give this some thought. I know from others I have recommend and are now users, that slow contact is probably the biggest (and for me only) negative using Plusnet.