Systems error

I have had a wifi contract with Vodacom since 2019 and filled in the forms with all my details including banking details. They deducted for the first 1/2 months and then stopped . When I enquired about this they told me its because they did not have banking details for this reason . I went back to the supplier that sold me the contract there after everything went down hill. I received no call to inform me that the payment was not received I noticed that the wifi was off few months later I phoned in to confirm whats going on they transferred my calls with no help. I decided that I must make final payment. They told me that I have been handed over. The lady just dropped my call . I feel that the operator was very unhelpful and that Vodacom could have done better by calling to let me know the way forward. They stopped receiving payment in October 2019 because for some or other reason the banking details was wrong but the very same banking details paid the contract when we started