Advice on borrowing money and repaying it

Questioner

A friend lent money to a so-called girlfriend. The agreement was that she would pay the money back with a certain amount per month. This happened once and now she comes up with a different excuse every time. The agreement in which she promises to pay the money back is in the mobile phone in an app conversation. Is there anything we can do about this?

Lawyer

If it is clear from the WhatsApp message that your girlfriend indeed owes a sum of money and also the amount, your friend can consider sending a final letter of formal notice to that girlfriend with a term (for example 14 days) to still proceed with payment. In that letter, your friend can already claim the statutory interest. If that friend does not respond or does not pay the amount within the term, your friend can start proceedings. How much is the borrowed amount?