Changing from Investor Loan to OO. Need advice.

Partner and I recently moved into our investor property. Called our bank (one of the big4) to ask about switching to O/O they informed me to call back after 12 months as we had to hold the investor loan for at least this amount of time. This was back in December so only had a few months to wait. Called back to make the same request, bank now telling me we have to go through full re application and have income reassessed due to high LVR. The rates they quoted were rubbish so I challenged why would I go through a full new application when I’d be better off shopping around if I have to do a full new application anyway? At least another lender would re value the property as part of the application process. During the course of the conversation the rep on the phone was quite rude and kept talking over the top of me. I must of said “I’m going to make a complaint” anyway, hang up and minutes later there’s an email in my inbox ‘complaint lodged’ I didn’t actually lodge a complaint how does this person even know what my actual complaint was? So now I’m spiralling.. I’ve told the bank we now live in the house, I’m not going to stay with them, but i can’t apply for new loan elsewhere for at least three months due to partner starting a new job. Will the bank likely take action against me because we now live in the house but the loan is unchanged and will stay that way for a few more months?