Magento order being charged twice

Question

I'm a Magento developer, and one of my clients has been experiencing a major issue. Some of their buyers/clients (very random) are being charged twice or more the amount of their orders, yet only one order is being created each time. So far it has happened 3 times and 2 in the last 3 weeks.

They are using the Authorize.net CIM Integration module. After investigating a bit I realized that they were not the only Magento e-commerce site experiencing this issue. As it's nearly impossible to reproduce the error and there is no pattern, most people seem to believe it could only mean there is a downtime, timeout or the server is being overloaded.

For the time being the only things thus far that seems to have helped some people eliminate this issue is to tune the PHP configuration (such as the max_execution_time ) and the CURL timeout variable.

I was wondering if anyone ever encountered this issue and if so do you have more information on why this is happening and how to fix it? So far the little information I've found hasn't been to concrete, looking for solid facts, explanations and solutions. Thanks!

Answer 1

Some visitors are very impatient. When they click some form button and feel no action then they will double click this button.

So place some java script code to disallow second click for few seconds or place a text around button don't click this button twice.