I contacted National Debtline to get clarification on the interest and charges, they basically shot down advice given out by people in forums such as this and told me that if particular things such as charges/interest are stipulated in the original agreement, then it is completely enforceable.

Even if they're highlighted in a credit agreement?

To add to this, the debt is now with MMF who seem like lovely people from some of the posts I've read on here!

Hello, This is my first time on here, like most who take out a PDL I got into it without really knowing the potential problems they cause. Unfortunately I could not pay back the loan in full as a result of ill-health and a seriously depleted pay packet, I contacted Mr Lender and asked if I could set up a repayment plan. They agreed but advised me that they will continue to apply interest and charges until they receive the first payment, in 3 months the loan increased from £472 to £921!! I would like to know where I stand with regards to having the £449 interest/charges written off because there are some points in the agreement highlighting the charges, see below: If you fail to make a repayment on the due date we shall charge you a late payment fee of £20. Unless we have agreed that you may defer making payment the following provisions will apply. If we have to write to you regarding your breach of this agreement, we will charge a fee of £20. If we have to serve you with a default notice we will charge you a fee of £20. If any payment is not paid on its due date, then you will be liable to pay us interest calculated on the overdue amount at the Borrowing rate until the date of actual payment. Interest will be payable before and after any judgement we may obtain against you. You will compensate us for any costs or expenses that we incur in enforcing the terms of this agreement. Without limitation, this will include legal costs, and costs incurred in tracing you and any costs of our agents in attempting to collect any sum you owe under this agreement.