Misinformed Sale

I tried to reverse an upgrade since 2 weeks I received it but was told to sit tight things will get better. Its past 3 months now and my 600GIG I receive monthly I can never reach due to speed and not being told this special would be throttled. Its like winning 1million Rand and only receiving 1c a month! I logged numerous calls and no one can fix this. I want my upgrade reversed so I can get something that works. This is the mail Vodacom sent me - is 300GB HOME internet) / Line speed is throttles as per contract stipulations/Speeds depend on the amount of users on the network, Radio conditions and amount of device on the router / Advised the client accordingly / Store to change/migrate/reverse upgrade the contract at no cost to the client due to the store misinforming the client.