Shocking overbilling since Upgrade

My wife did an upgrade (on the advice and consultation of an agent from Vodacom Brooklyn Mall) in February. We were not told that the contract was only really due for expiry in 2 months time, so we were double billed for a handset in March and April. This apart from multiple incorrect loadings of add-ons and standard features in the upgrade contract.

We accepted the mistake and paid the two payments. In May the old handset billing continued and a service request was raised. In the June invoice we were greeted not with a refund , but rather with a full charge of R7,920 for May's "equipment".

Thanks for a R10k bill Vodacom. I will be suspending debit orders and reversing previous payment D/Os until this can be resolved.

Prior to the upgrade there was never an issue, but now I need to literally audit my statement every month.