What are the options for extending a tourist visa in Bangkok for Pakistani passport holders?

Several comments suggest that obtaining a tourist visa extension in Bangkok is straightforward and can be done without an agent. Users highlight the requirements, which include the passport, a passport-size photo, the TM30 form, and some time to fill in the forms. There is skepticism regarding the need for an agent, especially for Pakistani passport holders, with one user indicating that it may be difficult for such passport holders to obtain a 30-day extension, possibly only receiving a 7-day extension at the discretion of immigration officers.