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.
1. Yes we agreed to pay $64k to draglet for 16 month, not $53k
2. Yes
3. Yes they agreed
4. For example, im my trading platform was a few options such as Margin trading, Swap trading, Real-time chart and etc.
We told draglet for complete our project then we will pay your first payment($4k) 30 days after complete of project. they agreed, but now not!
5. Yes, BitPay invoice:
https://bitpay.com/bill?id=HnVnxo6bnCrHAtNPgf7SM4&resource=bills6. Yes, but we didn't access to server root, we changed our DNS.
7. NO, we don't trust them because they broken our condition. now we want refund ~$1100
8. Yes, $4k
They want that we pay item by item, (for example for Swap trading, we must pay $15k) but question, why we sent offered monthly payment to 16 month?
Because we have business plan and we don't want pay item by item.
They broke their promise!
Ok, as far as I understand it, draglet required extra payment for extra features.
You wanted those extra features to be included in the monthly rate, they wanted payment for development costs up front and considered the monthly payment a "hosting" fee for their service.
As long as we can't verify what's been agreed upon, I wouldn't consider this scam.
Most likely, it's a misunderstanding of terms.