SIM is not working.

Hey,

So I don't know if the problem is the SIM or my phones.

My mum sent me a SIM and I have activated it and bought a plan about 2 days ago I think it was. 

I have tried the SIM in 2 different phones and no service on both. I have been in the settings on both and it is saying SMARTY card is in and on but just no service/emergency calls only. 

I've tried airplane mode, taking SIM out and back in and restarting phones several times. 

Anyone got any advice or solution?

Thank you.