With this new bank approach to close accounts unless you have long term visa, own property or are married, does the DTV visa suffice to keep the bank account or is this still deemed a touristic visa

Hi!

I got a Student ED Visa from last August and it ends on the 15th of June. However, I have to been in Bangkok on the 17th. I went to Malaysia to get a Touristic Visa while coming back but for some reasons they didn't give it to me. I first thought about overstaying instead but since I have to come back a couple of days in Thailand in mid-July, I won't take any risk.

So I now think about doing an extension of stay of 7 days. Is it possible with a Student ED Visa? Cuz all the informations I find are about touristic visa. Is it easy to get it? Because technically I could leave on the 15th but I'd rather not miss my meeting on the 17th, but if there is big chances I get rejected I prefer to save my money.

I can provide an Invitation Letter for my meeting, Passeport photocopy, ID pictures, what else?

Thank you!