Why not just come in for a talk? It seems that many loaders/fuellers etc. are a bit hesitant to just come up the stairs into the cockpit. They will certainly not be bitten away, and even less so if they have an issue that they perceive to need the crews attention!
So while the doors are still open, just come on in and speak Your mind eye to eye with the crew. While they are not, go grab a headset and do not rely on pantomimes to get Your point across. The spoken word has much less potential for misunderstandings than most alternative means.