Code error

HI,
In the Search Results Layout I have a parameter for “Payment terms” from Listing Setup custom fields.
When I enter to use a Field Type “Select” it shows perfect the payment terms in front end as follows:
Terminos de Pago: Western Union;

but if I select the field type “Check Box” the fields show like this with some characters inside:
Terminos de Pago: a:4:{i:0;s:3:”L/C”;i:1;s:13:”Western Union”;i:2;s:10:”Money Gram”;i:3;s:2:”–“;};

This my code for payment terms:
<span class=’hidden_details’ style=”color: #808080; font-weight: bold; font-family: arial,helvetica,sans-serif; font-size: 8pt;”>Terminos de Pago: </span><span class=’hidden_details’ style=”color: #000000; font-family: arial,helvetica,sans-serif; font-size:
8pt;”>[paymentterms];</span>
<div class=’clearfix’></div>

Can someone give me hand how to fix it?
Thanks,
Tulio