AI based caller who can converse/ communicate

I am running my store and I have 1000 customers in my database. I want to offer them a special discount 5% on their next order so I want a system to call them automatically (auto dialer) and talk to them in a robotic (as natural language as possible) so they can select their answers and I understand their responses. Ideally, I want AI or smart caller software which can converse and answer them, it is even better.