Unfair refusal of contract,dissatisfaction at customer service

I have an account with Vodacom and pay them every month never skipped a payment. Today i decided to take a contract and I am told I dont meet vodacom score ?Why on earth would they do that? I pay my accounts on time they should I just wish I can take my business else where this is ridiculous. I have a contract with them for almost a year, they should give me a good customer service. The lady that I spoke to asked me if i have ever skipped a payment? i told her look at the history, not once have i skipped, so disappointed with the customer service .