Product: Debt collection

Hello, Right up front I must state that my issue does not exactly fit into any of the categories listed. It relates specifically to the time period involved with this alleged debt, which I believe would most closely fall under the category of " time-barred '' or statute of limitations. 
I am providing a very high level overview here and will include my letter to the NJ State Consumer Affairs Board as an attachment. The letter which was originally submitted in XXXX of this year ( XXXX ) is more detailed, unfortunately I have not received any type of response despite numerous attempts to follow up. 

1 ) On XX/XX/XXXX I received an invoice from XXXX XXXX XXXX stating that I had an outstanding balance of {$830.00} for services rendered ( initial billing date ) of XX/XX/XXXX. 
Since this was the 1st time I was hearing of this outstanding charge I requested further information.I also inquired as to why this was coming to my attention at this time, having never received previous notice. XXXX responded that they had just recently undergone a computer systems conversion and this balance appeared on an exception report. They also claimed that I had " most likely '' been previously notified but they could not verify this due to those records ( notifications ) no longer being available after the computer conversion. 

2 ) XXXX did send me copies of what records they had relating to this balance, which were listed as unpaid insurance claims. I then called and forwarded the information to my insurance carrier- Horizon XXXX XXXX XXXX XXXX ( XXXX ) of New Jersey XXXX However the dates and claim numbers XXXX provided did not align to the service records that XXXX XXXX had on file for me. After an extended period of back and forth between both entities XXXX informed me that they would need to forward this matter to their archival research dept and that they could not give me an estimate of how long it would take to complete my research request. I relayed this information to XXXX who told me that they would put my case " on hold '' pending insurance response. 

3 ) On XX/XX/XXXX I received a letter from CDI Affiliated Services that my account had been turned over to them by XXXX for collection. I immediately replied to CDI with the full explanation of the status of the situation, explaining that I was waiting on insurance information. 

4 ) XX/XX/XXXX I received documentation in the form of Explanation of Benefits ( EOBs ) from XXXX showing that the negotiated covered expenses, which XXXX agreed to, totaled {$410.00} and that a check was issued in this amount to myself. I forwarded the documentation to CDI who verified with XXXX and adjusted my amount owed to {$410.00}. 

5 ) The outstanding issue now is that I no longer have personal financial records from this period due to the amount of time that has elapsed. I believe that I deposited the insurance check into my bank account and issued a personal check in it's place, which was my normal course of action at the time. The problem is complicated by the fact that the bank no longer exists, having been acquired by another institution in the interim period. I am extremely familiar with the ... .challenge this presents as that bank was my employer at the time. The chances of my getting a copy of that paid check are minimal at best. Had I been notified in a more timely matter I either would have still had my personal records or been able to contact the bank while it still existed. This brings me to my question of is there a statute of limitations pertaining to billing for a past debt? 

Thank you for your time and attention with this matter. I sincerely appreciate it.