or even try going online

http://www.vodafone.com.qa

or here

http://www.vodafone.com.qa/go/en/getyournumber

and find out.

So far there are stores in Villagio mall, Landmark mall, City center as well as associated merchants.

Do a search and you will find lot's of info.

PS: numbers can go from free up to more than 300000 QAR.