Yes but - seems that the color would be more immersive.
My Dad simply put a small lamp with a "10W" nightlight bulb behind his TV that turns on/off through the aux power port on the TV box. The room is pretty dark - even during the day. So this light actually makes it more comfortable to watch TV. I did something similar in my house too.
A simple light - that changes color. That goes to 10. That cool DIY in the link - goes to 11.
A couple of choices (been on both ends of this)
1) hold back on monthly subscription/service fees
2) threaten to sue (need to have proof that it is costing you money - angle is violation of contract)
3) Escalate within your management - let the CTO/CEOs talk to each other.
Yeah - maybe you recommended them and you've learned since then. Don't hide it because somebody will find out soon enough. Be proactive and get internal help figuring out how to solve the problem. Always be professional - you can let them know you are unlikely to buy again but don't needle them on this point. Get a few demos from competitors in the meantime.
If you paid for something and didn't receive it - you have an out. However, if this was some optional component that they were going to develop - then your learning is for next time - get the full demo. I think you are unlikely to get money back to cover your costs - unless it is big (take the CA govt vs Oracle).
As for talking to your management, make sure you can word the conversation in terms of a business case. Talk about how this is costing the business money (with numbers), how the business isn't able to achieve some growth (holding you back).
Biology is the only science in which multiplication means the same thing as division.