New deck build, Aluminum decking will be used and looking for advise.

I have a project underway which is taking a lot longer than anticipated. Was supposed to be done end of May/ Maximum 15june. They currently say that the decking I chose is OOS with no clear indication on when its to come in. Besides that I am here to question and get some guidance. They insisted on using untreated lumber for my project as due to it having built in rails no water should touch the lumber and it will be kept dry. I live in Quebec where we have nasty winters and very hot summers. Fast forward to now.. they have had the framing/untreated wood in the sun/rain since June 9th. They haven't covered it at all and all the skirting is almost touching the ground. I started to notice some dark spots. Anyway at this point we're assuming our whole summer is lost with this contract.. we've had to buy a ladder for the pool or else we wouldn't be able to use it all summer.

Looking for any advise or suggestions etc... this is our first big reno and it's already a stressful situation for the cost.. they required 50% deposit to accept the project and order and then another 25% to start building.

Will attach photos of the current project.

thanks.