Discovery Run around - Procedure codes and Network Hospitals

I was diagnosed with a blood clot inside a varicose vein. Went to a specialist (urologist) who needs a Angiogram to see where the veins run, before surgery. As the doctors administrator has been trying for over a week to find a hospital on my plan that has a angiogram available I phoned Discovery - 3 phone calls - two dropped after 3min each, I get through their 1 minute message and waited another 3 minutes before my call was answered - gave them my 5 security question answers and was then put on hold for another 5 min after explaining my situation - only to be transferred to another department and be placed on hold again. The hospital authorization department - told me that I needed a ICD10 and Procedure Code, but could not give me any help with them. When asked which network hospital could help me with the procedure they referred back to procedure code - which they cant help me with? So now I need a procedure code to get authorization to a hospital that might do the procedure, none of which discovery can help me with?