Its costs me 30 $ everytime i send money to my gf i send 15 000baht everymonth... how can i get arround this are there cheaper ways

Companies like http://www.canadianforex.ca/ will charge you $15 for that amount, you may get a better exchange rate, but you will need to sign up for an account.

Send her a bank debit card from a Canadian bank in which you have set up a specific account for this purpose.  You deposit only what you want to give her, and she uses the local atm to withdraw in Thai baht.  Cost is 150 baht per transaction, up to usual maximum of 20k baht (some bank variations, but that's close).

Send her a bank debit card from a Canadian bank in which you have set up a specific account for this purpose.  You deposit only what you want to give her, and she uses the local atm to withdraw in Thai baht.  Cost is 150 baht per transaction, up to usual maximum of 20k baht (some bank variations, but that's close).

 

In addition to the Bt150/180 foreign card fee applied by Thai ATMs  as mentioned above, there will most likely be a foreign transaction fee applied by the "card-issuing bank" ...many cards carry a foreign transaction fee in the 1 to 3% ballpark and maybe an additional flat-fee also.  So if going the debt card route be sure to scope out the fee applied by the card also as the foreign transaction fee and the ATM usage fee can add up.

Mine has a Cdn$3.00 fee

 

Still much less than using SWIFT wiring.