Three problems here, all self-inflicted.
First - you took on a client before you knew how to filter garbage from real leads. classic.
Second - you should've spotted this in the first few days, not two weeks in. If you can't tell a bot from a buyer within 48 hours, you're not monitoring the data.
Third - you've got no system for testing or fixing. That's the real kicker.
here's what you do now. Learn how to kill bot fills and time-wasters on your forms. Check that your form questions actually match the offer and the audience - maybe they're right for the top of funnel, maybe they need qualification further down. test different form variations once you're sure the format itself isn't broken.
Two weeks is enough to figure this out if you're actually looking. And think about it from the client's perspective. Would they rather hear:
A) "First couple of weeks were messy, lead quality started rough as you saw, but we've been testing X, Y, Z. give it another X days and we'll have consistent high-quality leads rolling in."
Or B) "Leads aren't talking to me? Shit, I dunno, I'll figure it out."
Both say the same thing. One shows you're on top of it. The other screams "why the hell did you hire me?"