The money you spend servicing debt is the money somebody else earns on their savings. And many people (retirees are an extreme example) happily spend such money on restaurant dinners and new cars.
http://www.bankofengland.co.uk/publications/Documents/quarte...
According to your claim, debt interest just disappears while i know for a fact that it does not since i've used such money myself (earned on my savings) in the past to buy stuff.
If you look at page 3 of the document, it talks about how repayments are basically an accounting alteration of the debtors deposit account.
Meaning that said account is reduced by the mount paid, but does not show up with a matching increase on any other account ledger (the banks own or any other).
Debt and savings are wholly uncoupled, no matter what mainstream economics likes to think.