Contractor installed lower grade shingle than in contract

Hi, looking for some advice from more experienced people on how to best resolve this.
tl;dr: Contract says Landmark Pro, regular Landmark was installed instead. What’s the real difference in value between the two? Also concerned about warranty and quality of work due to this and other issues along the way.

We hired a roofer, a smaller company in Virginia, to completely replace our shingle. Our contract and agreement was for the installation of a CertainTeed Landmark Pro shingle. They installed the new roof and left behind some extra packs of shingles. I realized today looking at the package that it’s a CertainTeed Landmark shingle that was installed (NOT the Pro that we agreed on). Looking at pictures from the install day, all of the packs were this Landmark - not Pro - shingle. The roofer says the supply house must have delivered the wrong thing and he just didn’t notice on the install day, but that his invoice for the supply house says it should be Pro. He said that he will follow up with them to see what they could do - but his initial offer was to give us a price break of $800 (for a 29 square roof). He says that this is the difference in price between the materials, and that the shingles and warranties are essentially the same. [BTW, he stopped by prior to the install to verify the materials delivered by the supplier and was onsite for the majority of the first day of install. Very surprised he would miss this.]

I feel like this does not reflect the true cost to us of having the wrong shingle installed - I’m thinking about the life of the shingle (rated 10 years less), the shorter algal resistance (5 yrs less), and shorter SureStart period (5 yrs less), lower quality product, breach of contract, and labor costs associated with having to replace the shingle sooner than the Pro. Also - if they didn’t notice what shingle they were using, what other mistakes could have been made? This event really lowered my confidence in their work.

I want to believe that the contractor is acting in good faith and just made a (HUGE) mistake. It seems like it would be a massive waste of materials and everyone’s time for them to come out and tear off the brand new roof to replace it - but they would need to give a much larger price break for us to walk away feeling “okay” about the install, especially considering we’re still waiting for some other smaller fixes to truly finish the job nearly a week later. We also don’t want to be wasteful with having materials replaced completely. The crew also damaged a sentimental fruit tree during the original install.

Furthermore, we purchased a 10 year workmanship warranty with the original install, but don’t have confidence in the warranty or necessarily want to continue working with this contractor. He has been very flaky with regards to schedule and follow through. What options are available to us? What is the true difference in value, since we had the wrong shingle installed?

In Texas, the pro series comes from Shreveport. It doesnt say Pro on the bag. It has a small, blue box, after the word landmark. In the box is the letters, MD. Check that and see.

I think asking to pay 75% of the original price is a fair deal for both sides. I do find the landmark shingles in my area to be of higher quality than tamko, but no I would not expect either one to substantially out last the other. Ratings and warranties from the manufacturer the residential roofing world are mostly a sham these days.

Thanks for the feedback. We’re going to get a roof inspector out to make sure there aren’t any other issues, and it sounds like he wants to work to resolve it.