Slow administration

I am extremely dissatisfied with Mobicred. After years of being a customer I am ready to cancel my account and get a refund. I transfered money over and above what I owed them, hoping to make use of my excess amount to buy a product on special but they have yet to allocate my payment. It's been well above their 2 working day policy and after numerous calls, my payment still does not reflect! I am beyond frustrated with this kind of service. I may as well cancel this account if I can't use it when I need to