It appears that there is some confusion.
The living together for 2 years rule does not apply if your fiancée is coming to the UK to marry you within 6 months on the grounds that you are engaged to get married.
Further information on this category appears here
I would suggest that you engage an immigration lawyer to take your case up for you, they would need to look at all the paperwork unless you wish to appeal the refusal personally without professional involvement.
You may find an immigration lawyer near you through the law society find a solicitor facility or by using an online search engine.
Hope this helps