Timing chain replacement please

Hi guys
I've got the timing chain snapped, done some damage, now bought all the parts again but when to install the chain my Mecanic can't find anywhere the diagram or a a sketch or something, not even on autodata on how to align the marks on the timing chain with marks on the camshaft and the crankshaft. And I've asked mazda but they said that that's confidential.
Do you have the diagram.
Thanks

I brought my Mazda 6 in for its 6 year "big" service at an estimated cost of  800. 6 months prior the DPF light was on and I brought it to the same service centre. I was told that it was the turbo needed to be replaced at an estimated cost of  2000 but they had managed to get the DPF light to switch off so it might be okay (though they recommended the turbo change). It only came on a week before the service. During the service however, they decided the problem was due to the timing chain which needed replacing. This led to issues with the fuel injector and filters, a special machine was required to remove something that had moulded to the engine (sorry for lack of technical knowledge!), Then a vacuum pump needed to be changed, oil strainer needs to be checked - the list goes on. The bill is now up to  4,400 so far with another "problem" appearing every day. I am beginning to wonder if I am being scammed. This is an authorized Mazda dealer where the car has been serviced annually