The question to ask yourself is where did the problem lie. There are typically four reasons why a house didn't sell.
Communication, Price, Condition and Marketing.
The first three can be the fault of the agent or yourself or a combination of both. If you want to get your house sold you need to objectively sit back and see where the problem lies. Just about every home is saleable in 45-90 days. Period.
Below is a link to a series of articles about re-listing your home.
Ill leave you with one thought...
Doing the same thing will obtain the same results!
If you want to sell your house something needs to change.