There are a few things you can do to get this issue sorted out.
The best (and fastest) thing to do is to contact the provider directly. Their number and contact details will be on your order confirmation email. Alternatively, you can click the "Contact Provider" button from your account settings to email them directly.
Another option is to contact our support team & we will investigate for you. You can contact us on Chat Support directly. Simply quote your order reference number (ORD-1234) and we will investigate for you. You can also email email@example.com. For urgent queries, feel free to contact us on one of our support numbers.
There are many reasons why a provider might have missed your order. In any case, the provider will make every effort to have your items collected and returned as quickly as possible to offset the delay.