Vodacom ripping me off on my data contract

I've had problem with Vodacom data depleting quickly and they promised me to deal with the problem but they did not I am still experiencing data problem and I've just upgraded my contract because they told me I was having data problem because I was out of contract it seems like the person who got me into contract again was just selling me empty promise. I am not happy with Vodacom they are ripping me off I receive 50 gig on router and 30 gig on the other router but all the routers don't last me 20 days I need my data back. Vodacom has turned to be *********. Stop ripping us off as customer.