Problem whith recording a call

Hello everybody. I have a problem whith the recorded files. I found the files but the voice is in append. First the called voice e then the calling voice, in append mode. No file merge.

How merge the in/out voice in the correct sync ?
Any help ill be greatly appreciated.
Thanks in advance,

Problem was solved installing the nex sox version (1.4.3)overwriting the oldest (13.x).