VODACOM SHOCKING SERVICE

I upgraded a Data Tablet deal in December last year and received the tablet and sim card. Showing no signal after 24 hours I contacted them to see what could be wrong. They said the sim card needed to be activated and that I sould take it out and leave it for 24 hours and then put it back and it would work. Now 6 months later and after probably 10 more attempts to get this sorted it's still not working. 7 months of Data gone but they take there money every month. Gonna cancel the debit order and they can come fetch there tablet which my son has only been able to use with wifi. Absolutely shocking service....I have 2 other contracts and will cancel them too when they are done!!