If you are sure you are not the blacklist, you need to have the lawyer send the letter to the immigration office and asked them to issue one letter to you saying that you are not the one who is on the black list one of my clients got the same had someone similar name and have the black list, we did the letter for them
Same as my clients he got the same situation with his previous agency, don’t have his name on the system but have visa on his passport, recommend Vientiane but you need to book the schedule to the embassy, I believe Monday will be full schedule.