Hello,
I have read the project description and understood it. First hand, I don't do telemarketing but I can help you generate an email list of those 1500 people. You can reach out to them first with an email campaign and try to close some deals then you can have your telemarketer call them and approach them. Calls can be more impactful for someone who already know a bit through email even though they didn't respond to it.
Send me a message if you think that can be a plan and we need to discuss it further.
Best Regards,
Kuldeep Gera