Hi Michelle,
Yes there is a way to recover the debt.
First of all, if you have text messages that prove the agreement was for a loan that was to be repaid, then this will probably be sufficient evidence. Make sure you preserve them somehow and obtain a paper print out.
Second, you want to make a formal demand for the money. Write a letter of demand setting out the exact amount of money that is to be paid back and attach to it the receipt for the airfare to evidence the amount and for added punch a copy of the text messages to demonstrate that you mean business and you can back up your assertions in court. The demand should specify a deadline for the money to be paid, failing which proceedings will be commenced. You can find some pretty good templates and precedents for Letters of Demand online - just google it. Deliver it in person or by registered mail so you can prove that he received it.
Third, if you get no love from the first demand, send a second - saying basically the same thing but also specifying a date that you will institute proceedings if payment is not received. Also highlight that there will also be interests and legal costs to pay if he waits until legal proceedings are in action to pay the money.
Four - go to your state Small Claims Tribunal or equivalent and file a statement of claim - this will require you to attend a hearing and will cost a small filing fee.
Once you have a judgement against him, you can then enforce it through various means, but that's for another post.
