my diabetic dad has an infection

my dad 49 male, he's 189cm tall, and has type 1 diabetes. He takes insulin for it. we have a history in our family of having not the best immune system. (My dad was a heavy smoker back in 2000 but stopped around 2007) (5-6 weeks ago) got surgery for a severely ingrown nail to get it removed, getting it removed obviously gave him a wound, now this wound is infected. he has had the sack "removed" 1 time before 3 weeks ago but they didn't remove it all, he's on antibiotics and the infection has grown bigger and worse, my dad's a pharmacist and he's scared that the infection might've gone to his bone. But since I live in Denmark (free healthcare) they try to save as much money as possible by doing as little medical care as possible.

They just said he should be on anti-biotics for another 4-6 week's. But theres still pus leaking out from the wound and my dad is still in pain, were scared if they won't do something soon he's gonna have to get it amputated. What do we do??