@Mia *********
pardon me, but you should NOT 🚫 have applied unless you planned on staying in Vietnam until the decision is known.
When did you submit your DTV Visa Application in Vietnam?
If you are returning to Thailand, how do you know that you may not be allowed to enter ?
Rules have changed recently.
If you have a recent history over the past 12 months of staying in Thailand using Visa Exempt Entry and extensions, you will have a problem entering Thailand.
Without added information from you, it's difficult to give you advice on your situation.
Good Luck 🍀