Realise- Its the Principle of the Thing!

Why are T-Enterprise Charging their customers VAT when they are not VAT registered, they charged me a total of £711.00 and are giving me the run around since I asked on the 18th June for the Vat paid incorrectly to be returned to me. after 2 broken promises to repay me they now say 32st July for my repayment. Is this how to treat and retain customers?