Connection Denied Help Please

I use a proxy server for the internet (PrivateInternetAccess) and am not able to connect to a clients ftp server to upload files. I am getting the following error code:
[06:49:31] 13>Connecting to Port: 21
[06:49:31] 13>Proxy: Connecting to SOCKS5 proxy server Port: 1080
[06:49:33] 13>No connection could be made because the target machine actively refused it.
[06:49:33] 13>Client closed the connection.
Can someone please assist me?