Question

The nobles who presented King John with the Magna Carta were tired of paying unfair taxes; thus they demanded in their document that:

Answer 1

Thus they demanded in their document that the nobles must consent to new taxes.
They didn't want their money back - they knew that there was no way they could ever see their money again which is why they didn't even try to regain it. They also didn't want to abolish taxation completely - but rather lower the amount of money they had to pay.