UPMC Passavant

Review: Service for Lab Work done 10/11/2014 left a balance of $75.00 which the insurance did not pay. First statement was recieved and payment of $25.00 was made on 11/03/2014. Second statment received and payment of $20.00 was made on 12/11/2014. Leaving a balance of $30.00.On 1/2/2015 I received a letter from UPMC stating they attempted to contact me and were unsuccessful. I was never contacted via phone or letter prior to this. This letter states that I will be turned over to a third party collection agency in 10 days unless I respond. I contacted the UPMC billing department on 1/2/2015 wherein it was explained to me that they wanted me to set up a payment plan. As requested, a payment plan was set up for $15 for the next two months. It is only January 2nd and ironically, I just finished writing out my check for $30 which would have been payment in full. Why would they send me a threatening letter when my payments have been made in a very timely manner, each month?Is UPMC permitted to send threatening letters when payments are already being made faithfully on a regular basis? This UPMC practice is a waste of time and money. It does nothing but aggravate a consumer with excellent credit. Is this even legal?Desired Settlement: I only desire that some "higher-up" in UPMC review their policies to prevent what appears to me as a harrassing threat. Why??....would UPMC want to harrass a customer who is already faithfully making payments on their bill. If a customer skipped a payment or made no payment at all, then I can totally understand contact from UPMC. This has caused unnecessary aggravation not only for myself but also their office at ###-###-####. Thank you.