the best option Vodafone Post paid.
recently they started limited offer for Gold plan.
you want to be paid only 125/- QR
you will get
Voda to Voda = Unlimited free
Voda to Qtel = 1800 minutes
250 SMS
1.5 GB internet.

no need to change your old number they will switch to qtel to voda.

my opinion Voda best.