Spouse Visa

Hi, I am in a bit of a dilemna and hope that someone can help! I am an Australian citizen currently here in the UK on a 2 year working holiday visa which will expire at the end of this month. I married a British citizen about 5 months ago in London (we did everything correctly ie certificate of approval etc). I am in the process of applying for a spouse visa but have been told by HO that because I left the country last month for a holiday and had less than 6 months left on my visa, I will need to return to Australia in order to process my application. Does anyone know about this or a way around it?
I am also studying for a diploma (15 hours per week), so would I be able to transfer from a working holiday visa to a student visa from within the UK? As you can see, I am trying to delay returning to Australia if possible!!! If all else fails, would anyone know the time period for spouse appplications to be processed within Australia? I have heard differing reports, ranging from 3 hours (if personally visiting the British Consulate in Canberra) to 4 weeks. Anyone's help would be greatly appreciated!

This a duplicate of one appearing here so I have locked this one.