Very disappointed with the service at MTN Shelly Centre

Very disappointed with the service at MTN Shelly Centre. Very unhelpful and unfriendly staff. Asked person at the branch for the reason why my modem is not connecting for the last 5 weeks and said couldn't find anything wrong with my device or account. When I phoned the call center yesterday they confirmed it was because of a problem with my account. The modem is still not connecting after talking to the branch and call center. Paying money for nothing - no connection for 4 weeks now. My account is paid up to date.