It's not really clear what you're talking about, so I'll try to sum it up:

Draglet is a provider of white-label bitcoin exchanges.

1. you agreed to pay $53K to draglet for 16 months of service
2. you offered to pay $4K per month of service instead
3. did draglet actually agree to that offer?

4. launch of your exchange was scheduled for 30 days before launch? I don't understand.

5. you did a prepayment of $1100
6. draglet delivered an install script?
7. you now want to pay the first $4K after launch of your exchange?
8. draglet asks for payment of $xxx right now?

As far as I can tell, this looks more like a misunderstanding of terms on either your side or draglet's, or both.

I happen to know the people behind draglet and I'd be surprised if they tried to scam you for a few thousand $.
They're trying to establish themselves as a service provider with an ongoing income stream so they have almost nothing to gain from one-off scams for a few bucks.