Spam messages can come from the mobile number, or from the sender ID (DM-DUNKND or VK-UBERIN ) whose service you have used at any time. But SMS from these companies will keep on coming. You can block these messages in this way.
1) Open a spam text message through the Messages app.
2) Tap on Details shown in the top right hand side.
3) If you want that sender not to be blocked. But the notification of the message sent by him was not received. For this, you have to tap the button next to Do Not Disturb. After this you will continue to get text messages but not notifications.
4) If you want to block the sender completely, tap on the i button.
5) Scroll down and then select Block this caller.
After this you will never get spam message from that fear ID. Some spammers keep spamming you with multiple IDs. Each bulk sender ID has a number which can be seen after following the fourth instruction. In such a situation, you have to block each number one after the other. Only after this spam will stop coming to your phone. After doing this, you will never get a message from these IDs.
If you want to unblock any of these numbers then do this.
1) Open Settings > Phone > Blocked.
2) Find the number associated with the bulk sender ID. For example, Dunkin’ Donuts India uses the number +91 36386563 to send promotional messages.
3) Slide the number to the left to bring up the red Unblock button.
4) Then tap Unblock.