Business ProfileforRed Hawk Fire Protection, LLC

I requested an estimate to replace the defective fire sprinkler heads throughout our home. Red Hawk Fire Protection, LLC provided an initial estimate for the job on 5/28/2021 for $1293.68. I was asked for 50% down and the rest upon completion of the job. I paid $646.84. After completion of the job, I was given another invoice that I believed was for the remaining balance that also included an agreed upon additional amount due to the job taking more time and effort than what was originally anticipated. I agreed that the additional amount was acceptable.The job was completed, and we got the final invoice 7/26/2021, and we were satisfied that we now had a functional fire sprinkler system. Then on 10/14/2022 we received email from ******************************* at Red Hawk indicating that we owed the second amount on the original invoice. It was my understanding that the final invoice included the remaining balance, along with agreed upon extra amount (approx $400) for extra time involved in completing the job. That balance of $1098.80 was paid in full on 7/27/2021. The original person in 2021 who was working these invoices is no longer either at the company, or in a different position. Due to the fact that the second invoice amount was very close to the original estimate, I found it odd that it didn't include the second portion of the original invoice. I don't want to pay what they are asking after a year and a half since the job was completed as I believe the request is suspect. Please advise.Sincerely, ************************** ****************** ************.