Yes I am quite sure. They can write £100,000 bond in the contract BUT if they only actually spent £10,000 then that is all you have to pay them.
Even then as a creditor you can write to them stating at what rate you can afford to pay them back - say £50 a month for many years. There is little in law they can do to compel a lump sum or any increased rate or repayment.
Cheers
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