Hoffman Music recommended rebuilding it first to get maximum resale value. I agreed. The agreed upon contract was that Hoffman Music would rebuild the instrument, sell it on consignment, take the cost of the rebuild, and their commission from the purchase price and send me a check for the remaining funds. This was a single transaction where there was no implied nor expected possibility that there could be a debt owed by me at the close of the transaction.A few months after dropping off the instrument I received a check from Hoffman Music. I deposited it in good faith that they had done their accounting as they said they would. Eight or nine months later I received a bill for the sum of $1391.36 to cover the cost of the rebuild of the instrument with no other explanation. I called and talked the the representative that wrote up the consignment agreement and he said that the accounting department had neglected to take out the cost of rebuilding the instrument out the the proceeds of the instrument sale. I protested the excessively long time it took for them to discover their error and my responsibility for covering the cost of their error. He said the manager would call me back the next day. I never heard from him. I did however get a bill a week later. I wrote a letter contesting the bill and asking for documentation demonstrating my financial liability for their accounting error. About a week laterI received another bill showing that I am 30 days overdue in paying the bill with interest on the balance is accruing monthly.Hoffman has been selling instruments on consignment for many years. When I cashed the check I had faith that with their experience and expertise that they would carry out due diligence in looking after their own economic interests in the accounting of the transaction and issuing of the check. Once "they" issued the check "they" determined the amount of my portion of the transaction setting the final closing amount. It is unfortunate if the amount was incorrect. This was not my responsibility. Once that check is cashed in good faith the transaction is closed. Had Hoffman discovered the error in a timely manner, put a stop payment on the check, sent me a letter explaining the circumstances, and reissued me a check minus the repair fee, I would have had no issue. Nine months later is not a reasonable time frame to request a redress of "their" error. Their accounting error should not place me in debt nor negatively impact my excellent credit rating which they are threatening to do.