Reading through your question it sounds like the addendum to the contract was not clearly written. It sounds like whoever did the addendum for you just gave you the right to do the work but not to release the money to you to do it should the seller not get it done.
Did you have an attorney? I am not sure because you said that " my attorney who is holding the money in escrow will NOT release the funds..." then later in your questions you say the "problem is that the seller has an attorney and I don't"...
Who is the title company? They may be able to help.
Angela "Angie" Allchin
Century 21 Rauh & Johns
The question that comes to mind is, why won't your attorney release the escrow funds? And what happened to your attorney?
Could there be more to this? What was the hold up on getting the work done sooner?
The bottom line seems to be that you would benefit from legal advice....and probably the best place to start is wiht your original attorney.
I had a similar nightmare where seller did work (new heating systems installed)and warranty didnt cover me; so be glad you oversaw and paid it yourself
Too bad your escrow instruction didn't direct the attorney to release the money to you if the work wasn't completed within the 3 months by the seller.
In any case this is a legal issue and you need a legal opinion (from an attorney ) for a solution.
That's part of the closing process and what he/she was paid for. I wouldn't hurt to ask your Realtor to assist you, too.