What usually happens with this type of fraud:
1) Fraudster sends you a forged cheque as a deposit, say $300, and books your service.
2) Shortly thereafter the fraudster cancels the service stating some emergency. They ask for a refund by e-transfer or Western Union, the cancel request goes like this... "Sorry, an emergency [mother had heart attack] so I can't get back to town for a while, I need to cancel. I feel bad about this, just send me $200 back. I really need the funds immediately to buy a bus ticket to Halifax -- my mom needs me. Keep the balance for your trouble, I'll stay on the line to confirm the refund".
3) The victim says OK, and sends back $200.
4) 2 days later the bank bounces the forged cheque and takes $300 from your account. After the dust settles you are out the $200 sent to the fraudster.
This is a common scam, as a banker I saw it regularly -- but usually, for a lot more, $1,500 was common. Variations are done by phone, by strangers approaching you at a bank machine.