I would have your agent push on the listing agent to make their client realize seller needs to abide by the agreement they agreed to. Otherwise, its breach of contract. (I don't know the specifics of the situation nor am I an attorney. Just giving an opinion as a Realtor) But, If listing agent didn't do their job explaining the process to the seller or advise seller in getting estimates prior to agreeing to repairs as a result of a home inspection, maybe listing agent will agree to reduce their commission to seller to reduce cost burden on seller which can be applied toward repairs or price concession. A listing agent won't want to do this and it may not be their fault. But, it will get the listing agent to take action to try and get their seller on board that not following a binding contract which they agreed to can have repercussions. Hopefully, it doesn't get to a point where you have to threaten or get an attorney involved. But, someone needs to make the seller realize you can't just renege on a binding contract. If you feel its serious enough it may be smart to get legal advice from an attorney on your options.
You can mention to listing agent that maybe in your mind the house is too expensive for the work that has been presented and want the home for less than what was agreed. I am being facetious but it would be making a point doing the same thing that they are doing to you. Or if you would prefer or be okay with a price concession in lieu of repairs, and it won't affect loan approval maybe thats an option seller can work with.