creating a high res pdf

Hi I'm self taught on in design, my sister has just started her own company and asked me to create the branding for her. I've created a simple text based logo on indesign with a curved box around and wanted to make her a high res pdf and jpg etc for her to use. They need a version to have no white background. I have done pdf presets and high quality print but its still a small file and pixilates when it gets larger. I spoke to adobe chat and they said it was high res just a small size (even though the file size is small) so I sent it over but now they are trying to use it on vistaprint for a business card and its coming up with a message saying the file is low res and should use a different file.

What am i doing wrong? They need the business cards for monday arg!