Contractor Issues...Need legal advice

[Steven Tenaglia]

Hired a contractor to do a what was supposed to be a small renovation project.  Renovation was supposed to be $11,450.   Start to finish. 

Basically after 3 weeks, behind schedule & him not showing up to job for a full week and catching him in many lies, (saying he purchased flooring when it turns out he did not among others) we decided to part way leaving the job unfinished leaving me to find another contractor who could come and finish where he had left off.

I had paid him $7500 @ this point and in my numbers probably owed him about $600 or so more for materials ( lighting & tiles) in the house.  I told him to send me over a detailed invoice with receipts so I could pay him and be rid of him.  After 3 weeks he sends me what he calls an invoice,  more like numbers on paper, no description and way inflated prices.  Some work we never even discussed him doing.  To the tune of $1650.  About $1000 more than my numbers.    

He sent me a text that I had to today to pay.  I told him, your numbers are heavily inflated and you didn't provide any receipts?  

I never signed any form of agreement or contract with him.  It was supposed to be a quick simple reno.  I told him I'd pay up to $800 if he signed a lien waiver release form.  His response turned into a cursed filled uneducated email.  

Home is on the market and is getting great reviews.  Can he put a lien of the home?  Can I take any action before hand to prevent further waste of time and money? 

Any suggestion is welcomed since this is my first situation with a contractor.  This is in GA, I know every state has different laws.  Thanks in advance.