Goodyear Eagle NCT5 according to goodyear.com.au are OEM for Fairmont and Fairmont Ghia and mention that they meet the requirements for braking, cornering and wet grip. This probably means they are a soft compound tire and 13,000km in start stop traffic, or poor quality roads would mean higher than normal wear rate.
Eagle GA Plus are what are on my dads AU2 Fairmont and his car has done 62,000km and only had the first set replaced after about 40,000km. These GA Plus tires are advertised as "Improved total milage" tires. As such they probably perform worse then the NCT5's that you have however they last longer.
Its all a trade off unfortunately. However 13,000 for 'brand new' tires sounds like excessive wear.
Falcon Killer (if you believe what Ford Service Departments have to say about me)
AU II XR6 - October 2001 ~ December 2002 - RIP
BA XR6 - December 2002 ~ Soon to disappear if Ford CRC can't fix it....
45,000km service coming up - and i'll be asking for a sizable list of fixes:
* Gearbox (3rd time)
* Steering click (5th time)
* Brake Shudder (2nd time, and has the applied "Fix")