It can take a little while. Please allow at least 72 hours after an auction is ended before contacting us about items not being received. After that time has elapsed, if the item hasn't been delivered, you need to submit a support ticket as described below:
1. Go to the Battle.net Support website at https://us.battle.net/support/en/ticket/submit
2. Choose "Diablo III" as the game with which you need assistance.
3. Ensure that "Use a few words to summarize your issue" is selected.
4. Type in "auction house" and click Next.
5. Choose one of the options that best matches your problem.
6. Scroll down to the bottom of the page and click "Submit a Ticket".
7. Fill out your ticket and click "Submit".
Be sure to mention in the ticket that you've waited 72 hours already and still not received the gold/items.