How can I see more information regarding errors and declines
When your gateway responds with an error or a decline message you can go into the Transaction record and view the complete message under Gateway Response. This will usually provide a deeper insight to why the gateway returned the error. If you can't find the answer here you can go under the Gateway Settings and check the box for debug. This will help troubleshoot issues even more.
If you don't have a transaction record see our solution for this here.