Frustrated client who is not enjoying what he is been debited for

I purchased a sim card contract with MTN South Africa about 3 months ago and before I even used the sim card it happens that I moved from my original homestead to a new place obviously with different address. I have been calling Customer services and even went to store to query and asked for the address to be amended so I can be able to use this sim card... To this day I am still struggling with this sim card because I haven't got a service. The address hasn't been updated yet. Today again I called to follow up and I have been taken from pillar to post. No one in 4 different departments I have been transferred to be able to take accountability and get this resolved... I am a frustrated Client that doesn't even know what to do... The sad part is... for the past 3 months I have been debited for a service that I am not getting. MTN you are a very big Company and please do not neglect your clients like this... The lack of service is really appalling. All I wanted was the address to be amended and the latitude to be checked so I can start enjoying what I am paying for.