Overcharged By $5k Compared To Invoice, Bank Sided With Me In Dispute, Now I’m Getting Collections Calls

Location: Monmouth County, New Jersey

Earlier this year, I brought my cat to a vet hospital. When he was admitted, they gave me a detailed estimate in the range of $6,000-$8,500, for which I put down $6,000 at the time of his admission. I have a copy of this estimate.

When he was discharged, the vet hospital gave me a detailed bill/invoice of services, which totaled to about $10,500. I have physical and digital copies of this invoice dating to the date and time of his discharge—the digital one being emailed to me from the vet. However, they charged me for $9,500 more on the day of his discharge rather than $4,500, overcharging me by about $5,000 based off of their own records, and close to double the high end of their original estimate.

I reached out to the vet about the overcharge a few times, but they didn’t respond. I also have this documented. Since it was reaching the end of my time window for filing a dispute, I filed one for the amount by which I was overcharged. The vet wasn’t able to produce an invoice totaling to the charged amount, so the bank sided with me.

However, I’ve begun receiving collections calls about this $5,000 “debt,” for which the vet has produced no documentation for. What can I do to get this erroneous debt removed and for them to stop trying to collect? I know that the FDCPA exists, but I don’t really know anything beyond that. Also, since this is a vet, is there an appropriate vet/animal health related agency to contact?

Thanks in advance for any advice you have.