Immigration office in Pattaya is the only office in Thailand where they don't accept applications for extension earlier than a couple of days before the visa expires.
Either do what they told you or move somewhere else and use a different immigration office for the extension.
Always important to differentiate between official announcement and proposals.
We all know that the vietnamese government has proposed to open the country for individual tourists tomorrow. But there are also hundreds of posts telling you that the government still hasn't announced any details how this is going to happen.
Thank you for confirming for us that this is the reality just now.
Before there is an official statement from the vietnamese government no vietnamese embassy anywhere in the world will be able to grant visas for individual tourists.
Wait for the official announcement or choose another country.
There are now more than enough countries open for individual tourists travelling from Thailand.
It's of course true this has been all over the internet for several weeks now.
BUT after the initial announcement mentioning the 15th march nothing else has happened.
Travel agents,hotels, immigration, insurance companies and health care providers in Vietnam are still not able to make any arrangements for incoming individual tourists because they don't know the rules.
How is that going to work smoothly in 3 days,?????
Nobody can answer that question because the Vietnamese government has until today not yet published any official guidelines. As mentioned above there isn't either any official announcement regarding availability of visa for individual tourists.