Make sure you know the difference between a TM30 and a op day report. TM30 is required within 1 say of arriving at any address in Thailand to stay overnight, and is done by the homeowner to advise the government that a foreigner is staying there. Hotels do this each day for guests that check in that day. A 90 day report is a self notification that you must inform immigration where you are staying every 90 days you remain in the country. If you exit, the 90 days resets to count from your next entry date. You need a TM30 (initial report of where you are) to file a 90 day report.
Change your travel agent if they aren't professional enough to do a simple Google search or even look up the visa policy of Thailand on Wikipedia, or even better, on the website of the Thai embassy in Australia, especially after you inform them they are mistaken. Also shows how seldomly this agent must deal with bookings to Thailand if they haven't kept up with Thailand's visa exempt policy change that has been in effect for several months already. Maybe find an agent more familiar with Thailand to help with your booking? Otherwise they are likely pulling travel advice from the same general googled sources as you could do yourself and therefore add no value to using them.
visa exempt entries for Americans and 90+ other nationalities changed from 30 days to 60 days as of mid-July. There is no longer a need for getting a 60 day tourist visa. Just like with 60 day tourist visas, a 60 day visa exempt entry can be extended one time per entry for 30 additional days, thereby giving you 90 days stay. Just show up with your passport. Nothing else needed, although you could always be asked for proof of an onward ticket, proof of funds, or booked accommodations, as has always been the case, but it is highly unlikely for Americans to be asked for this.
Why do you need an agent? It's usually done by the consulate in your home country, which agents can't help with. You can't apply for the DTV from within Thailand. Agents can't go to immigration to process these, unlike some other visas. You have to prove you are physically present in another country for that consulate to help you.
It's one of the most common procedures done by thousands of tourists every day. Don't let it stress you out. It is extremely simple and routine. But read the guidelines already posted so you bring the proper documents with you.
since this visa must be issued in other countries, and rules vary so greatly from one consulate to another for how the funds must be proved, it doesn't seem like something most agencies can help many people with.
