If you make a bug report, a Game Operator can look into the issue
I assume you have an open research slot, are not already researching artillery, and have the resources needed.
I know it's very unlikely, but besides those parts mentioned by Odin, have you already researched Infantry level 1? Also, have you maybe already researched artillery and just simply forgot and it's finished already?
It seemed like such a waste to destroy an entire battle station just to eliminate one man. But Charlie knew that it was the only way to ensure the absolute and total destruction of Quasi-duck, once and for all.
The saying, "beating them into submission until payday", is just golden...pun intended.