Paid account in full however VVM still insist their is money outstanding and this increase monthly

I am writing to formally raise a concern regarding a prolonged and unresolved billing matter involving YVDW Audiologists and VVM Attorneys After waiting over a year to receive my account from YVDW Audiologists, I was subsequently handed over to VVM Attorneys for collection. I have since paid the full outstanding amount directly to YVDW Audiologists and have sent VVM proof of Payment. Despite this, I continue to receive monthly SMS notifications from VVM Attorneys claiming that I still owe money. Alarmingly, the amount they claim is increasing over time. This is both confusing and distressing, given that I have paid and informed them. As well as the fact that I received an outstanding account from the Audiologists a year later?? I would appreciate urgent clarity and resolution on this matter, as it is causing unnecessary frustration. I respectfully request that both YVDW Audiologists and VVM Attorneys review the records, update their systems accordingly.