Fix iPhone iOS 6.1 Unknown Blank Messages & Failed SMS And iMessage service

Finally, I fixed this issue of not being able to send and receive SMS, including the blank unknown SMS.
Few days after I updated iPhone 4 to iOS 6.1 I noticed some sets of Problems with the device.

The problems are:

1. I couldn't send SMS and iMessages.
2. Receiving blank SMS from unknown sender.
3. An SMS is being sent constantly to a UK number +447786205094 and being charged for it. 

Whether it is an issue with the jailbreak or with iOS 6.1 or even 6.x i don't know. 
However, these simple steps outlined below did the trick and solved the problems

Step 1

Launch Cydia and let it download its packages.

Step 2

Click on search and type in Handcent SMS

Step 3

When Handcent SMS shows up, click on it and download to your device. After download, respring springboard.

Step 4

Navigate to the Handcent SMS icon on your screen and click on it. All your messages would be displayed.

Step 5

Finally, try sending a message and you will notice that it will get delivered . You can also try receiving a message. If you can't receive any message, try putting off iMessage.

For the incessant text message to the UK number, it is caused by iMessage trying to activate the service. Just go over to Settings>Messages and turn off iMessage. You can do the same for Facetime. Once iMessage is turned off, you will notice that the messages to the UK number will stop.
Although, the main reason to this problem might be that you have multiple back-ups on your computer for multiple devices. 
While restoring contacts and other things, your mobile number may be wrongly displayed on iMessage. To fix this, a reset of network might be necessary and reboot.

There it is folks. I hope this help someone

Please drop comments to educate more on some things that you also did right that fixed other issues.