was this a mobile home? by 'Title Number' as in motor vehicle? This might be the original title number the mobile was issued by manufacturer, and when it was set on its' foundation it would have been recorded as real property and a deed created, thus eliminating the title.
If the home was never set on foundation then it would still have a title, not a deed (for example if the home was located in a mobile home park on land lease)
That happens, especially on older homes. A manufacturer's tag or plate might still be visible somewhere on the frame if you look for it. wipe the dust off, take a photo and try to track down the manufacturer if they are still around they would have record of their product serial number/title number.
otherwise you go to the courthouse with all your documentation of ownership etc. and ask for help what to do. In NY where we are an attorney state, this sort of thing gets resolved prior to or shortly after closing. West coast though, it's handled through 'escrow' companies....they can be shady with little recourse.
in any event, 6 years is too long to have your money sitting in escrow. Sounds like somebody just dropped the ball and forgot about you. Sorry to hear it.
If it's not a mobile home then this really sounds like you are being hoodwinked.