it's normally worth it in the end. I'd suggest calling them and putting more pressure on them to get it done. By the way, you'd get significantly more answers on ChicagoZ.com; a lot of the members have used Ultimate Z, especially considering they were a forum sponsor for a while.
Putting eBay "performance" parts on your Nissan 300ZX is like putting Pep Boys wheels on your Cadillac Escalade... even people on welfare know better.