Refund paid into wrong account and still awaiting

I am still awaiting a refund that is due to me since May 2015 . My bank details changed I went to the bank got a statement , scanned, emailed my id together with bank details and completed the change of bank details form to discovery and still not sorted . I got the following reference numbers from discovery: *** / *** / ***.<br> <br> I emailed my information to [Email Removed] . I made contact with them on : 11, 18, 22, 23, 24, 27, 29 June 2015 . I spend over R100 on air time already not sure what to do anymore . I did receive a call on Friday from discovery that everything is sorted however I got notification from my bank (FNB) that a credit was rejected as they paid into the wrong account .<br> <br> Discovery keep on using the incorrect old bank account details of mine . That bank account has been closed and I already provided discovery with the correct bank account number and still they are using the old account , Bad service from them . I want this matter sorted and give back my money that is due to me .