If you are not 100% satisfied with your software purchase, you can take a full no-questions-asked refund for 30 days after your purchase. Since there are no physical products involved the only condition for refund is that you must delete the software.
If you purchase any services, such as template customization or custom PHP work, there are no refunds for services since it's impossible to return the time. The exception to this is if you cancel a service before the work is completed but have paid in advance, in which case you'll be refunded for the unused time.
To request a refund, contact support. You can expect it to be processed within 48 hours.