Focus polan filter replacement every 3 months??

My vehicle went for a service during November 2013 and the polan filter was replaced as per standard service. During February 2014 the vehicle's fan did not work effectively and I contacted Ford Menlyn regarding the matter. They advised that the polan filter was blocked and needs to be replaced at my own expense. This was done around June 2014 and cost me R800. The vehicle was serviced in November 2014 and the same happened during February 2015. Ford advised that this is a standard problem with the Focus and I will have to replace the polan filter again at my own cost. This is not acceptable if this is known to them why do they not resolve this problem. My husband drives a Fiesta and never encounter these tipes of problems...<br> <br> Please contact me via e-mail.