How can I extend my waranty ?

I am from Costa Rica (sory for my English).  I bought my Inspiron 15R in the United States, from Costa Rica, through the web page on Dec/2013.  The product had multiple fails last year that were solved using the waranty. Now my equip failed againg but my waranty ended on Dec/2014.  I tried to extend it through the web page, put the request, they sent me an e-mail telling that a representative will contact me in the term of 1/2 business days BUT, the contact never hapened. I can't believe a brand new Dell product can have such a high rate of fails.  I need urgent help.  I need a replacement or, at least, a waranty extention, but I've tried every option in the web page unsuccesfully.  PLEASE, HELP.