In Romancing the Fiddle

Back in September, I rented a violin so I could fiddle. The rent was reasonable, $52 for 4 1/2 months plus a damage waiver. At the music store I was presented with a cheap Yamaha violin made in China. It was a disapointment but it would serve. I bought a book to learn with and got through a few lessons until I noticed that the violin did not sound right so I stopped playing until I got to the music store.
Meanwhile, my account was never charged for the rental. Last month they sent me a notice saying that my card was declined. It took them two months to find this out. Okay, not problem. The next day I get another notice saying that they were going to send it to a collection agency. That day I faxed them my card number and said to correct my last name. How does one get "Blanc" out of "Bouc"? Anyway, my account was still not charged. Friday, I went to the music store and complained. The owner, bless her soul, called her rep. I get home and there's a letter from the collection agency saying that I know owe $15 on top of the $52. I immediatly called the music store and she said that they'll get things smoothed over. Today, I go to check my online back accounts and found that they took the $52 plus the $15 out. So why was I charged and extra $15 when I sent the corrected card information to them before I got the notice that they were going to charge me $15?
In other fiddling news, I found a fiddle teacher! The owner at the music store gave me a rough estimate of $45 a month....for a once a month lesson. I'll have to check again with her but I might do it anyway.