You might try getting in touch with Terry at https://di2center.com/ .
Thanks - I’m everywhere these days 
(well, I tend to show up wherever people mention “Di2”.
Like bpm1055 said, I would also try a couple of different USB cables. Especially since you’ve tried running e-tube on multiple computers already. Normally you connect the SM-BCR2 to the bike, run e-tube, select ‘road’ and then click ‘connection check’.
Still, if it doesn’t work, what does it do exactly? Does it get past the “Connect the SM-PCE1 / SM-PCE02 / SM-BCR2” screen at all? (or just it just look for the SM-BCR2 until you click ‘Exit’?)
Also… does your EW-RS910 charge port work? Have you charged the bike before using the EW-RS910 and the SM-BCR2?
The shop probably used the SM-PCE1 / 02 - those plug into an e-tube port instead of the junction A port.