International roaming not activated on new contrac

I took out a new contract on my cell phone and requested international roaming from the male consulatant who assisted me. I asked for confirmation that the international roaming was activated. I was told yes. I am now in the UK and losing out on my business as well as severely inconvenienced as the roaming is not activated. Last week I emailed mtn and still no reply or activation. Furthermore it took Mtn an additional 3 days to activate my contract despite being promised a sooner activation by the consultant. Lies and poor service which do not sit well with me.