Such a mission giving me credit/refund for the missing item from my order!

Such a mission giving me credit/refund for the missing item from my order! Since 2nd December, I have been sent from pillar to post by their online customer service teams, both on emails and through twitter. My order (#***) was meant to be 2 pairs of the same sandal, in different colours (Black & Brown) but only the Black pair was in the box. I reported this on the spot, to their staff at the pickup point and they acknowledged the issue, knowing very well that the reason the 2nd item was missing is due to no longer having stock(not even knowing why they still packaged it in the 1st place, without making me aware of the out-of-stock item) for the brown sandal. The pickup point staff member (Monique) made it seem like such an easy issue to resolve but to date, no one is taking accountability, except for asking me a thousand questions & asking for barcodes I have no knowledge of. I even wasted my time, going back to the pickup point on 8th December to remind Monique of the same unresolved issue, which she promised she'd get back to me after talking to the resolutions team...to date, I AM STILL WAITING!!!!