We had a project with them and it was the most painful during my 15 years of IT. Their staff was subpar and made no effort to help out at all. We chose them because we had their product and we thought they can understand it the best but it wasn't the case. They had all the questions about their own software and were not able to analyze the data stored in it. When we told them they should know the answers, they wanted to set up a call for us with their own customer service where we could get those answers and then we can give it to the project people. 30% of their project staff was beginners.
We're a small company and it can be the reason they ignored us so much.