Go on the UK gov website, download the template for getting married abroad , fill in the statement, book an appointment at UK Embassy in Bangkok, pay the fee before going, take your wife to be with you , she needs her ID card for the Embassy . Sign in front of the officer when called forward ( this is a legally binding statement which if false you can be prosecuted for). After this get it translated into Thai . Book amphur and go and get married
Everyone asks for agents what will happen if at immigration offices everyone will get fingerprinted and photo taken so as to match those on arrival at the border or airport ? The technology is there it just hasn’t been implemented
Go to the office where your TM30 is registered and get certificate of residence assuming you are on long term visa or extension, you may also have to have lodged a 90 day notification
did you put in a hand written and signed letter by yourself stating you are paying for everything from plane tickets and all her spending in Aus , did you submit your own bank statements showing liquidity, did she submit a translation of all property she has in her name, did you state you will fly both ways with her and state you take full full responsibility if she breaks any visa rules. What you can submit as evidence is endless