New contract issues

I opened a new contract with Vodacom which I was provided with a new sim card ,but when the number was activated on the new SIM card I got another customer number. Now I am advised to do number change which will be billed on my account which that is not fair at all. I regret even opening a contract with Vodacom poor service my case was escalated still ongoing no update or response. Team leaders are also useless no assist at all.