Update.
I think I found the problem now. I should have described in detail earlier.
What I left out is that I signed up for a supplementary sim as well (total 2 sim cards, 1 data and 1 data+voice). I planned to use the main sim for my phone and the supplementary sim for my MIFI device, so that I could connect this to 2 laptops.
I didn't actually think this would happen but when I swapped the sims over, it finally showed 4G on my MIFI, however on my phone, the 4G is gone and instead it shows a "H".
Not sure why one sim is 4G and the other is not, is this normal? If not I will be contacting China Unicom about it.
Main card 4G but secondary sim only have HSPDA (3G+)
Does anyone know if this is true?
The secondary sim card has no china roaming option, only the main sim.
I plan to use the main sim for my phone and take that to china without having to bring my MIFI device with the secondary sim.
Say if I get them to switch the secondary sim to 4g, I am not sure if the china roaming will be switched over too?
If not, then this would be perfect for me.
Heres an update.
I went to a different china unicom store today and described my problem to them.
They told me that the plan I was on, shouldn't be able to add a supplementary sim which I did and they gave me 2 options.
1. Refund the added 38hkd/month contract for the supplementary sim.
Or
2. Continue to use the service with the secondary sim in 3G.
Also they said they can't switch the secondary to 4G.
I chose the 2nd option to leave it.
Hopefully the speed isn't an issue for me as I plan to use this sim for business purposes.