No powerbank and again suspended

Have a home rooter my internet has been off since this morning. As i did open the contract my email address was wrong and my internet was then also suspended. Had to pay more then i was told when opening account. Nothing was said bout prorate. I just saw the amount when i went into mtn. The telesales guys offered me a powerbank which i did not receive yet. Very bad and since the internet is off today i think i will need to go into store again and rather cancel my contract. Did call the 138 number they told me to call back in 1hour. Why