I've downloaded the LiteCoin Core for the Mac (High Sierra 10.13.3) in order to use the testnet for testing an online shopping cart. I'm not looking to mine any coins, just use the wallet. The application loads up correctly when connecting to the normal wallet, but when I add testnet=1 to the litecoin.conf, it won't connect to the peers. When I look at the debug log, I see

2018-03-01 14:37:02 connect() to 104.236.211.206:19335 failed after select(): Connection refused (61)
2018-03-01 14:37:03 connect() to 173.209.44.34:19335 failed after select(): Connection refused (61)
2018-03-01 14:37:03 connect() to 173.209.44.34:19335 failed after select(): Connection refused (61)
2018-03-01 14:37:04 connect() to 66.178.182.35:19335 failed after select(): Connection refused (61)
2018-03-01 14:37:04 connect() to 66.178.182.35:19335 failed after select(): Connection refused (61)
2018-03-01 14:37:05 connect() to 173.209.44.34:19335 failed after select(): Connection refused (61)

I've tried adding an RPC user/pass, but still no go. Error 61 seems to relate to the service not running on the port on the destination machine. I'm in an office environment, so cannot make any network changes. Is there anything I'm missing?

Here is my current litecoin.conf

rpcuser=litecoinrpc
rpcpassword=mypasswordhere
testnet=1