I have a voice recording that I recorded on my MPMAN MP3 player .... it is an ACT file. when stopping the record mode it said it was saving it , but I cannot open it as it says it is corrupt and unreadable.

The file is there as is reads 27mb but I cannot open it .... anyone have a clue to recover or repair the corrupt ACT audio file or a way of getting into opening it

Thanks in advance