"Xray and ultrasound booking line"

This is about the Southampton X Ray and Ultrasound Booking Line.

My GP gave me this number and told me to call them for an appointment for an ultrasound. After numerous attempts and finally calling, to book an soft tissue US, which, according to the doctor's request, should be urgent (since for 5 months they have not been able to diagnose me and prescribe the appropriate treatment), they told me that they do not make an appointment by phone and they will send me a letter with a booking for home address during the working week. However, 2 weeks have already passed, and I still have not received the letter and the booking, respectively, too.

Am I misunderstanding the meaning of the word "urgent"? In my understanding, "urgent" means at least in the next few days, not weeks or months.