It's tough to provide you with meaningful information on such sparce details. Anyone can sue for anything but it doesn't mean they will get their wishes. If the work was done by a reputable and certified repair company and you have provided reciepts for the required work, one might believe you have fulfilled your obligation.
A simple but important observation is once someone obtaines legal services......it's probably best to do likewise.
If you used the NC standard Offer to Purchase and Contract form 2T, you should refer to section 4(g) CLOSING SHALL CONSTITUTE ACCEPTANCE OF THE PROPERTY IN ITS THEN EXISTING CONDITION UNLESS PROVISION IS OTHERWISE MADE IN WRITING. You should contact the agent and attorney who assisted you at closing. A letter from an attorney may end this quickly. If you appreciate an answer, please give thumbs up. For the most helpful answer, please say thanks with a best answer click.
Do you know what the buyers want? Perhaps you can come to some reasonable accommodation that will make this problem go away, you can move on with your life.
I am an agent who sued a seller for fraud and I won. However, it took over a year, a lot of my time, and cost a total of $140,000, that the seller paid. Lawyers are obligated to go through mediation first, before it ever goes to trial. We went through mediation, the seller would not settle, so we went to trial. Seller ended up paying my court fees, his court fees, my lawyer, his lawyer, buying back the house. I was "made whole", seller lost beaucoup money.
Get a good attorney who will lay out scenarios and advise you. I hope it turns out well.
My own thoughts are while it will be aggravating and will cot you money to defend yourselves the buyers are unlikely to prevail as they closed and our contracts clearly indicate that by closing they accept the house in it's current condition. If you used a licensed contractor for the repairs then they should in fact be taking up the issue with them.
Sellers reading this should take note, it really isn't in your best interest to make repairs for a buyer, you would be much better if off if possible arguing over money (based on quotes) and to offer either closing cost credit in lieu of repairs or to write a check at closing to the contractor the buyer wishes to use. By undertaking repairs you put yourself in the position of arguing over the quality of the repair. Buyers should also prefer to work in this manner as it put you in the position of overseeing the repairs to your own satisfaction and getting any warranty that might come with the repairs. This can't always be done as there are lending requirements that can interfere but this is the best option in most cases.
The question you need to consider is whether it's worth the time, money and aggravation to defend yourself in court or whether it would be less expensive to negotiate a settlement even if you did nothing wrong. You may prevail in court but financially it may be a Pyrrhic victory. The best advice I can offer is to consult with an attorney to get a sense of what you may be looking at expense wise if you go to court.