Issues with Vodacom.

We purchased 4 x contracts in March 2020. The value per contract was roughly (not able to give the precise amount maybe R299) So the total amount per month should then be roughly R1200. We received an account of R1 957.02. There is a substantial difference between the two amounts, please advise. We also frequently receive advances, and we discussed this with the call center as well as the Wilro Park Vodacom shop, despite the fact that we asked NOT to send us any advances. We also have a problem with my *** number, as I buy airtime from time to time which are taken away without any permition. The number above is also in question is also doggy as I should get R175 per month, however, the amount sent to must be R175, however after a couple of days some of the airtime disappear in thin air and not be seen again. We also went through an exercise to stop all subscriptions through 31050 to make sure that they are blocked, however it still happens from time o time. From my side it seems as if there is some ***** practices?