Misleading customers to sign up cell phone credit facility

I was offered a cell phone contract through mobile standard bank. I am furious as my credit card was debited yet i opted for the monthly payment of R349 per month. I emailed customer services and called the contact centre and im on hold for 15min no one to assist....No response. The mobile app is also not user friendly....The billing option gives me an error now. This is misleading customers to buying cell phones on the credit card and not as per monthly option as offered.