NYC: Does a seller’s lawyer’s responsibilities end at closing? What about later issues?

In the middle of 2025, I closed on selling my mother's house. Since then I have had issues with some of the associated accounts, like utilities. The buyer has not made themselves available for meter reads to close out my account on some of the utilities. Other the utilities have been successfully transferred, so I don't think they're being intentionally difficult.

As such, I continue to receive bills. I have reached out to the lawyer I hired to represent me during the sale.

I have attempted to call over the past month, but the paralegal whom I worked with is always away and has yet to call back. She has responded in email with "non-answers". The last was one sentence "We closed last year, you need to settle this with the buyer."

Fortunately I have been patient, but it's wearing thin. This seems to me unprofessional behavior. Is basically my only action now to deal with the buyer directly?

Any suggestions in what I can do? I have no phone number of the buyer, the only possible communication would be via letter.

TBH, during the contract process it seemed they were more in a rush to get it over with than truly looking out for my interests. I guess I chose the wrong lawyer, live and learn.