Firstly you should have enough credit on your account. After that you can visit this link http://www.bitlanders.com/shop  for buying Mobile Number. 

So I would like to buy Etisalat 10 $ Mobile Credit, please click on Buy Button , 

After that you with face to this option 

Click on My ORDERS Button

You Will see this Step

Usually After 12 Hours Or 24 Hours Your Order Will Be Ready For Use, So Now you can Press On REDEEM NOW button For Reading The Number like this

Congratulation . Now You Can Use It To Your Mobile,