Buggy Software and extremely poor (worst of any vendor I've used) customer and account support

From my experience, the worst product support and customer service of any vendor we use.

After we signed the contract, I reached out for help with training and never heard back. Then our first bill arrived for far more than what the contract specified, and there was no way to reach them. Calling their support phone number results in 90+ minute hold time (this has happened 5 different times - including being cut off and other times ending in my team leaving voicemails that are never returned). We've also tried emailing the customer support email address, emailing the (alleged) account manager listed on our account and submitting tickets into their support portal. Every channel has gone unanswered. The software is buggy and the interface is poor. If they offered even a minimal level of training or support, you could possibly overcome their product deficiencies, but as mentioned, you can't get them to respond to any support requests.