I'm using Appointmments to schedule the removal of vehicles

Hi!

I'm using Appointmments to schedule the removal of vehicles auctioned in auctions conducted by our company. SERVICE PROVIDER is the subsidiary where the car is and the SERVICE is the  auction name. Each subsidiary has capacity to attend one customer every 20 minutes and there are vehicles in the same auction in all the subsidiaries.

The problem is:

When I select an auction (SERVICE) and then a subsidiary (SERVICE PROVIDER) can not schedule the concurrent schedules. I've tried to use locations, but also did not work.

What's better way to do this?

http://www.leilaolegal.com.br/

Regards