Billed for phonecalls

According to my current plan on my vodacom online profile, I have 75 anytime minutes, yet every month when I receive my account I am paying for phone calls even though I have many free minutes available.<br> According to my profile I am carrying over almost all of my free minutes each month, yet I am still be billed for my phone calls.<br> My R229.60 contract is costing me over R450.00 each month<br> <br> I have taken a screenshot of my online profile but have not attached this due to security provisions