Try to find the reason why is frozen. Usually, a document is missing. So you can ask the second party of the deal to send it to you. It's easy with Export Portal.
You will need to know the reason for stopping your goods at the customs. Get acquainted with Export Portal's Library (https://www.exportportal.com/library_international_standards) , there is a lot of useful info there. Also, keep in mind that you can always message the party you are trading with on Export Portal, in case you need documentation from their side.
Before importing or exporting goods, check the section from the platform, where they have listed all the prohibited items in your country, it is very helpful and you will be more sure that the products you want to buy are safe and secure. Also check the “Customs Performance” section from EP Library, to see the documents required in your country to pass the customs.
Last time I made an order, my products were stopped at the customs because there was a document missing. We have discussed with the seller on EP and he sent me the required document. So, everything was successfully imported into the country.
First of all find the problem, why the products did not pass the customs, and afterward discuss the issue with all the parties involved in the order process and how to solve it.