Hi Steveinuganda,
Thanks for your post and welcome to the forums. It's great having you on board with us in the Community.
I'm sorry to hear that a new SIM was sent without you being informed. This is likely due to updates being done to allow our customers to get better value for money.
The SIM would need to be activated in the UK but if you have a friend or family member who can do this for you, they can then forward the SIM on to you in Uganda. It's worth noting though that as soon as the new SIM is activated, the old one will stop so you may be without a working service whilst waiting for the SIM to arrive.
If you have any further queries or questions, don't hesitate to come back to us.
Thanks,