Vodacom not keeping in line with contract

Every month I have to call Vodacom to load my data that is part of the contract. They log query and take so long to give me my data which they agreed to. I log a call every month they take so long to resolve the query. I mean I signed a contracts they offered 1 gig data more per month and they don't load it ever since I have to call they take 2 weeks to a month then it is resolved nobody calls back I even emailed them I went to Vodacom office showed them a copy of contract which they then loaded but this month again I logged a query 2 weeks ago still no response. It inconvenience bec then it costs me to buy data. Not fair bec they agreed to a contract<br>