Moh wav format?

I have several .wav files that we want to use for music on hold we receive them custom made in .wav format I get them 16bit pcm encoded and 8000hz. however the files do not play when uploaded. If i manually convert to mp3 then upload they are automatically changed to .wav and then work. but as i have LOTS in . wav format and thats the only way i can receive them (i can change the encoding) i would like to directly import .wav files not .mp3
I tried downloading the converted.wav but as far as i can tell its the same encoding

any help would be great as to what exactly the file encoding needs to be to play a .wav file

are they mono ? if not convert them with sox -c 1

ya they are all mono

post the output of

file (oneofyourfiles)
soxi (oneofyourfiles

compare with a working one.