Imessage, facetime and wifi

Recently i removed my sim card and inserted another sim card for activation. After that i reinserted my previous sim card and using it. But i am not able to use facetime/ imessages with the registered number and when i checked on my Name/phone number/ email, i am not able to find my number. When i tried to edit and add my number, it is saying cannot verify phone number, this phone number is not available. Why is that so? When am using my previous phone number with which i created my ID?

Also for some reason unknown i am not able to connect to Wifi. Previously i could connect to the wifi and also share my hotspot but i couldn’t now.

Please help..