An automotive dealer borrowed $ $8500$ from the Bank of Montreal on a demand note on May $8.$ Interest on the$$ loan, calculated on the daily$$ balance, is charged to the$$ dealer's current account on the $8$th of each month. The automotive dealer made a payment of $$$$1900$ on July $13,$ a payment of $$$$3600$ on October$1,$ and repaid the balance on December $1.$ The rate of interest on the loan on May $8$ was $5\%$ per annum. The rate was changed to $5\mathrm{.}6\%$ on August $1$ and to $6\mathrm{.}2\%$ on October $1.$ What was the total interest cost for the$$ loan?