Double billing by DotFnb for 7months

For the past seven months I have been billed for two Samsung S4 devices, of which I own one.The branch was immediately notified and they promised to rectify the error. They were notified again in September, again in November and December, and claimed they thought the matter was sorted, they again promised to rectify and refund, but they didn't. I went back again on Monday 26 January and Wednesday 28 January 2015, I was promised the matter will be given priority and will be sorted, but still. I feel DotFnb has taken advantage of my calm nature and simply done nothing to assist me. If I were the one defaulting on payments for seven months then they would've been very quick to list me. If this is the way business and customer service are conducted by this division of FNB then they have lost a customer in me. More should be done by them to rectify this, other than just apologize, it's too late for that now.See how quick I'll get a response just because I went onto hellopeter, this is really pathetic.