With the same relentless enthusiasm, I soldiered thru countless websites and finally. . . (what a crock !!)
I Googled
Primary Direct & found another number, 0161 9061713. At the time I tried it everyone was in bed so it went to voicemail, but the old default of pressing "0" passed it through to the switchboard recorder !!
Coincidentally though, I'd already tried 0161 9061600 and got the same recorder the others also went to.
# am:5-8-04: Gave
0161 9061600
a try to see if it was switchboard but it's just another sales line. There are probably more in between 1600 and 1660 if you fancy playing !
One of the sales staff advised me that they don't have a Switchboard which doesn't surprise me with the latest call centres.
BTW, testing the number sequence you gave revealed -
0161 9061660 - Sales : Voicemail; 0 goes to main v/mail
0161 9061661 - No Line
0161 9061662 - Sales : Opening times announcement
0161 9061663 - No Line
0161 9061664 - Sales : Voicemail; 0 goes to main v/mail
0161 9061665 - Rings out (no answer)