It looks like you can fix it in the javascript on the page... find this:
WAValidateNM(document.ecart_checkout_form.exp_year,'- Invalid credit card year format',2010,2020,0,'','',',.',document.ecart_checkout_form.exp_year,0,true);
The second number is the maximum... set to 2020...you can just change it to a larger number. Change it to 2016,2050 and you won't have to worry about it for a while.