Campaign purchases are usually instant, but note that sometimes automatic activation can take up to 24 hours. If however, after that time any of your campaigns have the status "pending", please make sure to follow this procedure:
1) If money was deducted for the campaign from the payment processor (i.e. PayPal) you paid with: Do not open disputes on the payment processor, but simply create a support ticket with the payment details so we can resolve it for you quickly. Do NOT delete the pending campaign in this case.
2) If money was not deducted from your payment processor for the purchase, then there was an error in the process and you can simply delete the pending campaign as it was not paid for.