It's very easy to make up a reason for denying a visa. But not actually send to the embassy. Google them. Lots of complaints, but they are becoming a monopoly in this field.
THIS SHOULD BE THAI VISA ADVICE GROUP AND TOD DANIELS!!!!!!!!!!!!!! Not Bangkok Expats
While you can rely on networking and friendly advice from the kindred souls at "Bangkok Expats Group" on Facebook, some situations call for professional assistance.
On December 31, 2016, Thai Immigration imposed a rule change for all countries: exiting by land border, previously granting the foreigner 15 days, has been increased to 30 days, but can only be done twice per calendar year, meaning January 1 – December 31. Countries with a bilateral agreement with Thailand, including Laos, Macau, Mongolia, Russia, and Vietnam are excluded from this new rule.