Reseller Server Got Hacked

I have been a client of Afrihost for over 5 years now. I have always received great service and products from them. I recently started my own hosting company and purchased a hosting reseller from Afrihost. I sold my first hosting contract and setup the domain. We built the website yesterday, and today when I walked into the office my domain was hacked. All the passwords I used were generated from their password generators in the reseller's admin panel. They are unhelpful, and told me that I am at fault. Now I am left in a puddle of shame of having to explain this with my client. HOW EMBARRASSING!!