Eli has agreed to repay a debt by using the following repayment schedule. Starting today, he will make $$500$ payments at the beginning of each quarter for the next two years. After two years, he will make $$1000$ payments at the beginning of each quarter for another two years, which will pay off his debt completely. For the first two years, the interest on the debt is $7\%$ compounded monthly. For the next two years the interest is lowered to $5\%$ compounded annually. Determine the size of Eli's debt as of today. $($Hint: Timeline really helps.$)$