PW lock code accuracy issues

I have a iPhone 5s that I have been trying for 2 days to detect the pw. It has successfully decrypted the PW on 3 separate occasions however it continues to provide me with the wrong code. So I am forced to use the start value to narrow it down.

Does anyone have advice on this as obtaining a single PW can prove very troublesome.

I am open to any questions regarding this situation.