Why can't I receive messages on my samsung from peoples iphone?

I use to have a iphone 4 contract and I upgraded to the samsung galaxy s4 I swapped the sim cards but I still have the same number the old sim card is not in service and isn't in a phone. The problem am getting is my friends with iphones get the imessage when they go to text me which doesn't go through to my phone but when they turn it off and on my name goes green lets one message through then goes back to imessage. Its starting to annoy me i've rang up vodafone and they just said it need to update so I followed there steps but its still happening

what do I do?

Only your carrier can help you.

You must log into your itunes account, go to account information, manage devices and remove device. This will immediately resolve the problem… Good luck

  • Why don't I receive alerts or a notification when I receive a text and I already checked my settings? I adjusted my setting and even put the ringer and notifications on and put the volume and ringer on and I receive no alert, no pop up, alert or notification when someone texts me. Why? This is the iPhone X! I went to the cell phone/ carrier store and they didn't help me. They said to go to the apple store or check the settings. I already adjusted the settings. So what do I do now?
  • Why can't I receive messages on iphone 5c when data is off? When I'm not using data or Wi-Fi I can't receive texts sometimes. The messages are not converted into sms. Can I fix this so I can receive messages?
  • Why can't my iPhone receive SMS messages on 3G? I have a 3GS which has just started having issues with 3G connection. It refuses to receive SMS messages, but I'm able to send them. I have tried to reset network settings, turn off iMessage, restart numerous times to no avail. The only way I can make it work is to turn off 3G, turn the phone off and on which allows SMS to be received. Am I missing something obvious as to why it's having a mini meltdown?
  • Why can't i receive text messages from iphone users? So i used an iphone before switching over to the galaxy s8. For some reason, i can't receive text messages from people who use an iphone. I still have the iphone i previously used and it gets all the imessages from people but it just doesn't go directly to my galaxy s8. Is there something i have to do to fix this? Do i have to wipe the sim card on the iphone in order to get iphone users texts?