"Surgical gauze from C-Section"

I had an emergency C-Section at Monash Clayton earlier this year. Everything went well I believe, but I noticed still having a small brown spot. I reported it to my GP and was told that it could be due to weak pelvic muscle. 

However, around 6 months postpartum, when I had my period, a surgical gauze suddenly passed out through my vagina when I went to the toilet at home. It was after business hours so in the morning, I reported it to the hospital and was told investigation would take 35 days.

Meanwhile, I also paid a visit to my GP and had an ultrasound referral for clearance. 

I had to contact the hospital several times for an update as they didn't contact me at all. Maybe they are too busy.

I got the letter attached via email and was told that their investigation shows that everything was accounted for correctly during my surgery. Hence, there was no lapse or negligence on their end.

I felt that the investigation was not thorough and they are covering their a** so no one would be liable for this negligence. It feels like there was something fishy going on.

I have high respect at this hospital, with my second pregnancy, I would say I was attended appropriately as I was considered a high-risk pregnancy then.