Michael Jackson is going to have some very unhappy fans. But it is not his fault.

Tour production delays caused Michael Jackson to push the July 8 kick-off date of his 50-date residency at London’s O2 Arenas back to July 13. Three other July dates also had to be moved to March 2010. Now, fans who purchased tickets from reseller sites like eBay for the original dates are unlikely to get a refund.

“Major ticket sellers and resale marketplaces that take customer protection seriously guarantee refunds,” said Jonathan Brown, secretary of the Society of Ticket Agents and Retailers, in London’s Guardian newspaper. “However, people who have bought tickets from individual or unauthorized resellers might be left out in the cold, with little chance of getting their money back or being offered a ticket for the new dates.”

With many tickets showing up on eBay, a company spokesperson told the paper that they moved fast to make sure that tickets corresponding to the postponed dates were removed from the site as well as preventing sellers from posting tickets for those rescheduled dates.

“However, people who have already bought tickets for the postponed concerts from an individual seller will not be able to get hold of a refund unless they can persuade the seller to give them one,” she noted.

The affected concerts are July 8, 10, 12 and 14. Tickets for the July 8 concert will be honored at the new July 13 start date. The other three shows have been moved to next March 1, 3 and 6.