concerned about hygiene and bad attitude

On the 11th of October 2015, (my birthday) a male companion took me for lunch at Mama Luciana's in La Lucia for my birthday. I ordered the Alfredo pasta meal which comes with prawns and when I got my meal there were no prawns in the plate so we politely asked the female manager in a black and white striped shirt to assist as she walked past our table. She did this and when the meal came back there was more in the plate. After a few nibbles I noticed a strand of hair which I removed silently, then I became suspescious and opened the middle of the plate contents and found a lot of hair that looked like it was deliberately placed there. We quietly asked for a manager without causing alarm to the other customers, and showed a male manager in a red checkered shirt. He took it back tried to offer something else but I could not stomach anything solid after what I saw. I just want an official apology and to notify the management of that fact that this happened in the first place. We were not charged for that particular plate, but my day was ruined and I haven't been able to eat anything solid since. Was I not meant to complain considering it was the wrong order?