Anyone have IPs NOT pay for screening?

[kjpmrp]

In March 2009 I independantly matched with a couple to do an ED. I went to a local hospital/repro clinic to have my screening done. Unfortunately things did not work out and we did not cycle together. Today I received a bill for the cost of the labs and ultrasound. I know the work was originially set up as a 3rd party pay and the bill even mentions "Payment received" and then "Check returned". I am thinking about sending a letter explaining that this was a 3rd party payment and including the IPs information, but I assume they already have that and are billing me because the IPs aren't paying.

Anyone dealt with this? How did you handle it or resolve it? I'm kinda thinking I am SOL and am going to have to pay it anyone so it stays off my credit, but I am feeling super irritated right now!!!