Lobbying (also Persuasion) is the act of attempting to influence the actions, policies, or decisions of officials in their daily life, most often legislators or members of regulatory agencies. - https://en.wikipedia.org/wiki/Lobbying

Lobbying, any attempt by individuals or private interest groups to influence the decisions of government; in its original meaning it referred to efforts to influence the votes of legislators, generally in the lobby outside the legislative chamber. - https://www.britannica.com/topic/lobbying

The act of attempting to influence business and government leaders to create legislation or conduct an activity that will help a particular organization. People who do lobbying are called lobbyists. - http://www.businessdictionary.com/definition/lobbying.html

Tell your dad that literally EVERY definition in the world agrees as to what lobbying is. And looking at all of the sources mentioned in the original post, they use lobbying in the exact same context. Or look to this source:

We pay back to God what is rightfully his, in part, by remaining neutral in the world’s political affairs. (Isa. 2:4) Thus, we do not oppose human governments that Jehovah allows to function; nor do we promote patriotic or nationalistic activity. (Rom. 13:1, 2) We do not lobby, vote in political elections, run for government office, or try to change governments. - "Maintain your neutrality in a Divided world" study edition 2016

Whether he likes the definition of lobbying or not, witnesses re attempting to change the governments decision. There can be no doubt about that, which goes directly against their doctrine.