When do you follow up on a client who decliend a contract, but looks like their other vendor has failed too?

I have a client who works with me regularly. They asked me to quote them for an e-commerce site. This is an extremely complicated site with over 1,200 products. Many of the products are similar, so I structured my contract around creating 500 products and then training their team to add the remaining products.

Their current site looks like it is from the early 2000's. The quote I provided was what I felt was fair for the amount of work we would be doing (SEO optimization and building all the products, categories, etc.).

They came back and said they had a friend who could do it cheaper. I understood completely, as my cost wasn't cheap, but that is because I knew I would do a good job the first time.

Well, it's been almost a year now, and the site hasn't changed at all. I've followed up a few times, and the responses I got were "Our guy is working on it." I get it is a lot of products, but my outline had us soft-launching within 3 months.

Since we are approaching the one-year anniversary, should I follow up again or just give up? Feels like an opportunity to go, "Your guy was cheaper, but looks like you aren't getting any results."