Hi Nura, lucky you. there should be a guide line on how to redeem your Santa gift on the message you received. If you have not been contacted by now or guided on how to receive your Tecno phone, you need to contact MTN support with the message you received on the gift.
You can contact MTN support via any of these channels:
1. MyMTN App
2. Facebook: @MTNLoaded
3. Instagram: @MTNNG
4. Live Chat: http://bit.ly/2OC5bHz
5. Email: customercareng@mtn.com
6 .WhatsApp: 09033000001