Bad customer service

I have been with Telkom mobile since 2012, started up as a contract now my sim is prepaid. I spend more than R500 every month on data and voice, today I needed to change my tarrif from Telkom more to SIM sonke and made a mistake of choosing broadband what what. I tried to reboot my phone while the phone was processing but unfortunately it has already registered. Now I am stuck with something I don't want for life since there is no way back. I am porting my number to Vodacom or cell c if I don't get help with this.