yes, we have tried to contact some of them, since we've been communicating with customers about their visa applications, the main reason they gave us for stopping halfway is they don't trust us, they have big concerns their privacy will be compromised

On your website, create a section where describe your process in processing the visas and indicate within that process what you will do to keep their data secure.

hmm, that's a brilliant idea, will try to describe that on the website