Natural Health Pharmaceuticals gave a free sample then sent another bottle and charged me $90. this was in 2007 Santa Monica, California

i sent for a 'free sample'.  it came.  did not like it.  a new order came and they charged me $90.  I sent it back.  the sent me a bill i would not pay.  they gave my bill to a collection agency.  it is also on my credit report that i did not pay this bill.  it has lowered my credit score.  i just got another letter and decided to call the company cause the collection agency is not nice.  they just want to get paid and i keep telling them i sent it back.  i was looking on line and seen this web site and that i was being ripped off.  i want to get this off my credit report and get this collection connection agency to stop calling.  Now this happened in 2007.  Yes i said 2007.  i have been dealing with this for 6 years.