"Saw a doctor - failed to diagnose a simple ailment"

Went to the Urgent care centre at Mayday, first time ever, as it was Xmas and GP closed. Had a small tumour which was frequently bleeding. Saw a doctor after less than a hour. Twice I asked what it was (I later learnt it was pyogenic granuloma from a more competent doctor, the private GP where I work). Twice he said he didn't know, but did offer to cauterize it with silver-nitrite, all the same. Although I declined as he seemed to discourage me with talk of high levels of pain. In the end he just gave me the small band-aid possible to replace the one I'd removed. Is it worth formally complaining? this doctor seems to be not skilled to practice.