Mango. Will not take good care of your valuables

I took my hand luggage onto the plane with me, but because mango will not enforce their own hand luggage rules, there was no space for my bag above my seat. The air Stuart offered to place my bag in an empty spot, asking if I had a laptop. A few minutes later, he returned with an orange ticket , stating that my bag was put in the hold!!! Horrified I asked about my valuables. He said there is nothing we can do now, as the doors are shut. On arrival at my destination, I waited at the door of the plane for my bag. I was told to collect it at the carosel inside the terminal. My bag was last out, no cell Phone, Strang huh. I have called and emailed mango. No response. Are they in cahoots with the *******? Is it them, their staff or a syndicate working from within? I have instructed all staff in the group not to use mango or SAA.