Multiplier miles not issued

On 27 April, I alerted Discovery Card to the fact that they overlooked a number of transactions at Shell Sandhurst when allocating my Discovery Multiplier Miles for April because it was listed on my statement as 'Sandhurst filling station' and consequently not picked up by their system. At the same time, I noticed that they didn't calculate my Multiplier Miles for May and I received zero miles.

I've since phoned them seven times to get this resolved and I keep getting told that it will be corrected in the next few working days, but it never materialises and has dragged on for close to two months now.

The issue has been escalated three times, which has made no difference in getting it resolved.