Mobile connection dealers and Mobilink franchisee were involved in porting customers mobile numbers without their permission to get credit and earning from company.
They were sending SMS to random people like
Dear customer you have won prize, kindly send MNP to 667, then forward received SMS to 76300 and (their mobile number).Several retailers used this method to port other mobile connections to Mobilink network and thousands were ported by this method. They get reward and free balance once a MNP is successful. Mobilink doesn't ask them to do this.
Every network has a MNP number and 76300 is MNP number of Mobilink, used to process MNP requests for customers who want to port into Mobilink network.
But it seems that PTA have taken step to prevent this scam by filtering SMS which includes number 76300 which will not allow those retailers to send fake prize winning SMS to others asking to send SMS to 76300 to initiate MNP process.
Try it yourself: write 76300 in your SMS from phone, send it to someone or to your own number. SMS sending will be failed or if sent, delivery will be unsuccessful and you will receive SMS delivery report as failed to deliver. (effective on all Pakistan mobile networks).
MNP: Mobile Number Portability service which allows you to change your network without changing mobile number.
PTA: Pakistan Telecommunication Authority.