bad service

was at the store to do an upgrade they changed system the one on customer care tell me one thing and the other one tell me something else... today when i phoned after issue with upgrade at store they say i can only upgrade next month but yesterday were told i could've upgraded in feb already. due to them changing systems 21 month etc... now they need to do vetting when store tried they said no phone this number and so forth..i never experience such bad customer service especially when doing an upgrade *** but mtn contract no is *** they need to approve it now but i never missed any payments