Take legal action
If you realize that your borrower (who may no longer be your friend at this stage!) doesn’t intend to repay you, send them a formal notice. This is a final warning before taking legal action. You can draft this document yourself (templates are available online) or ask a lawyer to help you. Your borrower must pay back what they owe you within a specific period, which is typically 10 days. If they fail to do so, the next step is a court hearing.
While paying a professional to draft a formal notice is more expensive, it will be more persuasive than drafting it yourself.