I expected unlimited low speed internet data

And hope that freeupmobile will allow me to buy it with cellnuvo golds.

I think you should make that suggestion to Cellnuvo support

I am willing to pay $3 each month for unlimited low speed data. But cellnuvo does not provide that kind of service, and it cannot find anybody to provide us that kind of service. I think freeupmobile has this potential since it provides wireless phone service.

Rp has this on a few deals on Amazon.

With 500 gold you can afford the yearly plan with unlimited 2g

Certainly I can afford it, but I would not pay over $36 per year for unlimited low speed data. I think the cheapest i can find is from tello, which costs $7 per month.

Nothing that great about unlimited slow data. Just get yourself a decent allotment of full speed and you won't have to worry about it.

It is gold. Not money from your pocket. Rp annual plans are great in Amazon

I experimented one month with fallback 2G on Tello. I had 200mb LTE, and mostly use an efficient browser (Puffin) on websites that are primarily text. I was around 100mb into 2G world before I realized I was dealing with throttled data. Yes, it was slower, but not horrible.
Sites containing lots of pictures loaded pretty slow, although Puffin would display text while still waiting for pics to load. Video was, of course, impossible.
I wouldn't want to live with 2G all the time. I'd love to have fallback, , since I know I could live with 2G for a while if I needed to, and wouldn't have to worry about Google Voice.

No it is not that great and that is why I will pay no more than 3 gold's each month for it. On the other hand, 56kpbs is enough for me, though 128kbps is nicer.