Proven Powersports — they have my bike and documents, but they didn't call me back

I bought the bike through the company Proven Powersports. As well as I have submitted the forms and documents for the registration and waited for the response. However, these guys kept silence and didn’t return any documents. I have emailed them and even left three voice messages, but no one called me back or even explained where my documents were left. Maybe someone can help me in this situation.