You can get multiple Entry Visa (METV) which covers you for up to 6 months, however every 60 days (or sooner if you want) you must leave the country. When you go back to Thailand you get stamped another 60 days. You can also get a 30 day extension for 1900 baht. So, your three months are covered as well as visiting other countries.
You just have to keep trying. The US embassy told me to change cards, change browsers, try different computer, clear your cookies. It took many tries over several days until
It went through. It turned out that it was the Thai banks that were denying it. Very frustrating!
My husband had this problem all week and finally got his METV processed yesterday. We called the Thai Embassy in NY and she told us to:
Clear the cache
Try different browsers
Press control and F5 on PC
Use a debit card
What actually happened is that we used a debit card and the Thai bank - Kasikorn refused it. The bank contacted my husband’s bank in the US and told them it needs to be authorized by my husband. When he told his bank it was fine to make this payment, he put the payment through on the application and it was processed.
This was a very frustrating experience to say the least. The Thai Embassy’s Visa Officer was fantastic, very nice and very helpful.