Poor customer service at MDSA

There are no after-sales services provided. I have called multiple times over the past few months regarding two invoices for the metal detectors I purchased online. Each time, they promised to email the invoices, but I have yet to receive them. If they can't even provide a basic invoice, I doubt they will handle repairs, warranties, or any other issues effectively. Additionally, the shipping for the first detector was only completed after I inquired about it more than two weeks later.