un-blacklisting

im very dissapointed that cell C is not able to resolve my query its been 3 weeks sense ive been doing the up and downs just to get my phone un blacklisted they all the required documents with them yet and they haven't assisted me, the call centre and the branch are both telling different stories my phone is still blocked and its been 3 weeks now no one is helping me, clearly im now paying for a phone that i cant even use.. its either they take their phone back that's not working and give me another phone ..ive been calling and going to the branch almost each day to get this resolved yet the un-blacklisting department is not unblocking my phone..im very annoyed and fed up with their unhelpful service..i need urgent assistance or they can take their phone back. the number in question is *** its a contract phone for blackberry z10