Taking forever to do refund

When granted a home loan by Nedbank we provided them with proof that we have buildings cover insurance for the property with another company. We therefore declined the insurance with Nedbank. <br> After a year of payment we were sent renewal documents for inurance. Nedbank has been deducting a monthly amount in respect of insurance, even though we have existing cover.<br> We informed them of the mistake and we have been struggling for days on end to receive the refund as promised.<br> We've sent all the documents they requested but still we have to wait. <br> This is quite disappointing seeing as we pay our dues on time.<br> Every time we've called the call centre we've been told something different.