Elite Mobile - R3000 voucher for upgrade

Elite mobile phoned my wife over 3 months ago and offered her an upgrade and a R3000 voucher if she accepts the offer . She did . The R3000 voucher would be sent to her after her 2nd payment had been done on the new contract . We have now done 3 payments and are on our way to the 4th payment and still no voucher . I have phoned Elite mobile on numerous occasions and each time I get the same response , they will email Vodacom to send the voucher . 6 weeks and still nothing . I have requested that the manager of Elite Mobile phone me and I am waiting for her call .