First of all, apologies for misunderstanding your original query. Fortunately, you have provided more input and framed the problem clearly. In the second sentence of your clarification post, you expressed your own inhibitions, which clearly highlight the need to focus on your interpersonal skills.
By and large, human beings behave similarly regardless of the setting. It is true that there may be less finesse, more tardiness, and a lot of lethargy in the behavior of bureaucratic functionaries compared to the private sector's reactions. However, I am sure they will not be outright curt, brusque, and unresponsive as you seem to believe. You need to change your mindset and refrain from worrying about becoming the subject of ridicule. Unless you overcome this mental barrier, you will always approach people with a sense of failure, leading to unsuccessful interactions and a loss of confidence.
Treat government officials with respect and dignity, and human nature being what it is, they will respond in a similar manner. If you carry preconceived notions that they will not be responsive, it will reflect in your body language, tone, and choice of words, resulting in frustration, irritation, and ineffectiveness.
My original suggestions apply to any setting but will be more effective once you start believing that you can be successful in your role and establish effective communication with anyone.
Best Wishes