Bad Service

I have had several contracts with MTN MTN over the years and now I have been let down terribly with the new contract I signed with Samson at Bedfordview branch. I am a 71 year old pensioner and signed up for the MTN M contract which on pg 17 of their leaflet is R315.00 exc VAT per month for 24 months.When I received the first notification it showed the contract to be R656.15. I immediately went and saw Fanie at MTN Bedfordview and he assured me he sorted it out on the computer for me. I also sent an email to customer care and had no response.My bank account has been debited the R656.15 for the first month. What has Samson added to my contract I am not aware of.I this the way MTN Bedfordview treat their loyal customers ?