US HealthWorks Medical Group Substantial overcharge on wrist guard Roswell, Georgia

I visited the US HealthWorks clinic on Holcomb Bridge Rd in Roswell on August 6, 2012 and was diagnosed with a broken wrist.  The doctor provided me with a wrist support.  I then saw on orthopedist who placed my wrist in a cast for 8 weeks.  After the orthopedist removed the cast, he provided me with a better wrist support than the one from US HealthWorks.  The orthopedist charged $36 for the better wrist support.  US HealthWorks billed me $112 for its wrist support, which can be purchased on line or in any drug store for $29 or less.  I sent US HealthWorks a check for $36 with a letter explaining that I was ok with them making a profit of $7, but to bill $112 for something worth $29 was price gouging.  They are still billing me for the difference and threatening my credit rating. They failed to respond to my telephone message, or to two letters.