We cannot tell you what's wrong with your code if you don't show it to us. Here's a simplistic example of text input I pulled out of my irc client. This does not consider TAB or Backspace. (actually it might consider tab and PRINT simply doesn't display it, I don't know).
doText = 0
msg$ = ""
do
if doText = 1
msg$ = msg$ + getCharBuffer()
print("> "+msg$)
else
print("| ")
endif
if getRawKeyPressed(13) = 1 // enter
if doText = 0
dotext = 1
msg$ = "" // clear any previously entered text
getCharBuffer() // to clear the current buffer
else
dotext = 0
// 'msg$' contains the user-entered text.
// Write it to a log or whatever you need to do here.
endif
endif
sync()
loop