Premium overcharged

I am a loyal MiWay client for the last 5 years. I called them to cancellcancel my policy as Outsurance provided a better rate. Seitshiro a senior consultant offered to beat the outsurance amount and if he could not I was welcome to move insurers. We went through the process and he offered me a good deal. I agreed to the new premium which is R320.00 less than the old premium. This was to be effective from the 1st of May 2015. A small change to the policy was made by myself I regards to my car hire. Seitshiro was not available but another consultant helped me. The premium was now R360.00 less than before. Today the 1st May 2015 my bank sends an sms to say the MiWay amount has been paid, this amount however is not the lower premium I was promised but rather much higher premium I was paying in previous months. To top it all off, today is a public holiday and the call center is only open for emergencies.