Avoid onine contract renewals

Dealt with a call center agent in order to renew a cell phone contract, with a new device. Asked for silver/grey...received gold. Phoned vodacom to inform them...was first cut off and then waited for more than an hour with no one answering. Phoned the next day...to be told sarcastically that he though women liked gold things. Was then told it is a very lengthy process to swap the phone to the colour that I requested, and that I should rather purchase a phone case in the colour I would like...at my expense? This is really terrible service, after I did not make the mistake I am being told to sort this out and to feel bad that I inconvenience Vodacom in having to swop the device? I am prepared to go directly to a Vodacom store (at my cost and time) to swop the device, but am told I cannot.