How long to wait for replacement head unit

[GSR]

Guys I took the beast in for its first service a few weeks ago and reported a faulty CD player. The authorised Ford service department confirmed it was faulty and said they ordered a replacement unit. After 2 weeks of hearing nothing I phoned them up and they said it was ordered and just waiting on the replacement to arrive. Its been another week now and still nothing. How long does it take and should I be calling Ford direct to see whats going on. Three weeks I think is a bit long.......