No worries! If you’re really not getting anywhere, there’s always the option to ask for your issue to be escalated via the Heat Pump team to the relevant Team Leader which might help get some movement.
Raising a formal complaint can also help get a response if you’re still not getting anywhere: Something not right with your installation | Octopus Energy
That’s actually the route I ended up needing to take to get a conversation properly started about replacing our 9kW.