You wi usually be allowed one extension before alarm bells at immigrations start to ring. It is best to go before your current visa runs out and make the application. Whether you are rejected and asked to leave or not again depends on the officer and or your entry departure history. There is no such thing as legally in any country if you are using tourist visa to stay long term. There are proper long term visas for every situation and some do get away with extending and going in and out and so on. But being allowed to continue doing so whether it is by extending in country or going out and coming back is at the discretion of the officer you face. They can and do have the authority to question and then deny any further extensions or entry if they so deem.
Since you were pulled aside, it will only be a matter of time before a denial comes. Because a tourist visa is what it means. Saying that you have a girlfriend will only be an accepted excuse before one unhappy officer decides that you cannot go in.
My suggestion is to try and get a longer term visa as soon as you can.
try asking a visa agent who will know the latest rules and also they can have a look at any stamp of your denial.
For me, I asked a friend to call them and show them and they advised what the proper things I should do and it worked. I was banned from entry for 6 months and also unable to apply for any visa for long stay for 2 years. I went in after the 6 month and was allowed in and stayed out for 3 years. But going through the airport in transit I was still asked to show onward flight. Once I showed it, no problems going in. Try to get professional advice so that the info is up to date.
I think those in this forum are not with Thai immigration though there may be some spies. So the "you" may be misplaced.
And those who contribute to this are mostly using their own experience or knowledge and should never be used as law.
Now back to your question. The statement you were refused entry means that something happened and you couldn't enter Thailand. This probably means that probably have a ban for a certain period and a probation period of another few years where your entry and exit will be closely watched. Regardless of your passport, your biometrics including face photo is already in the system and can be called up.
So in terms of a blacklist, it all depends on the reason for your denial of entry. There have been some who got denied entry and even after 3 or 4 years and a new passport, when they fly in, they get asked a lot of questions and were required to show an exit ticket. (this is my personal experience). But whatever it is, the laws are clear to all, if it has been abused and thus denial of entry is issued, then the person will need to be more careful and check with the laws that have been stated in the immigration website. Laws and rules do keep changing, so just check it out.
If you go to immigration to extend, you will only get a 30 day extension. So I think a border bounce, stay for a day or get an agent to facilitate and come back with another 60 days.
If it is a denial of entry, he will be asked to leave on the next available flight probay back to country of passport a d he will probably be denied entry for a period of time.
I got that in 2019 and my stuff had to be collected by friends and sent to me. I had to stay away for 6 months.
if you were in an ED visa, then you would hVe had to report to immigration every 90 days, either in person or by online with your TM30.
If then you wanted to extend, you should have gone to immigration again and then Change that back to a tourist visa for 30 days at the cost of 1900 baht. If you wanted to extend the Ed visa, then you should have a letter of confirmation and the various documents and then be given another year. If you overstayed, you would have been bundled to an exit point and you pay the overstay fine and be asked to leave. I think the person at the immigration may have said the wrong thing and I suggest you check your stamp on your passport again.
Kind of confusing. What type of visa are you on originally?
Basically, if you are an overstayer, you should be advised to leave and pay a fine. And it is always the person's responsibility to check their stamps for last day of stay and to make sure you leave or extend before then.
Unless you went to one of the immigration offices and applied for N extension and they used to charge 1,900baht for a 30 day extension.