Hangup detection problem

Hi everyone.
I’ve been playing around with asterisk for very short time.I’ve been having problems when I received calls. If for example the incoming call is terminated abruptly, for example I hangup upon finishing my voice message, my installation does not hangup and the channel is still busy.
I’ve been trying to set up hanguponpolarityswitch but with no success at all. I’ve been using Asterisk ui and find out that most of the configuration for the zapata channels is done in users.conf. Although some configurations are on the zapata.conf, most of the channel configuration are on users.conf.
Here is users.conf

[trunk_1]
group = 1
zapchan = 1
hasexten = no
hasiax = no
hassip = no
trunkstyle = analog
context = DID_trunk_1
trunkname = Line1
busydetect = no
busycount = 6
busypattern = 500,500
ringtimeout = 8000
answeronpolarityswitch = yes
hanguponpolarityswitch = yes
callprogress = no
progzone = us
usecallerid = yes
cidstart = ring
pulsedial = yes
cidsignalling = bell
flash = 750
rxflash = 1250
mailbox =
gui_volume = 2
signalling = fxs_ks
gui_fxooffset = 0
rxgain = 0
txgain = 0.0
channel = 1

and the zapata.conf

[channels]
context = default
switchtype = national
signalling = fxo_ks
usecallerid = yes
hidecallerid = no
callwaiting = yes
usecallingpres = yes
callwaitingcallerid = yes
threewaycalling = yes
transfer = yes
canpark = yes
cancallforward = yes
callreturn = yes
echocancel = yes
echocancelwhenbridged = yes
rxgain = 0.0
txgain = 0.0
group = 1
callgroup = 1
pickupgroup = 1
immediate = no

I’ve been playing around for almost two days with this issue and could not find the answer of it. Sorry I forgot the zaptel.conf

fxsks = 1,2
fxoks = 3
loadzone = us
defaultzone = us

Thanks in advance.