Payment issues and lack of service to help me

I took out a wifi rooter contract at vodacom chatz cradlestone mall in May 2017. I signed for a debit order for the first of each month. The issues:

1) There has not been one debit order from my account, vodacom cancelled the debit order.

2) Because my cellphone does not have a vodacom sim I have to go to the shop every month to phone customer care.

3) I have verified my banking details twice with the promise that the debit order will go off. Empty promises.

4) My wifi has been switched off twice and is off for the month of october but I still have to pay the full amount.

5) No one in store can give me an answer as to what is happening or even send me a statement.

6) After contacting and going in to the store for 5 months now it has not been sorted. I requested to cancel my account but no one will give me a way to do this.

I am very unhappy because my credit rating is affected by this account and I am not getting any help from any staff at this branch.