Missing and mixed up deliveries and no resolution in sight.

On 27 November I booked 9 boxes in at the Greenstone Depot of The Courier Guy. 4 were for a customer in Hartenbos and 5 were for a customer in Pringle bay. Hartenbos received 3 instead of 4 and 1 was for Pringle Bay. Pringle Bay received 5 but 1 was for Hartenbos. I have been phoning and emailing since 4th December when I was made aware of the mixup by my customers. It is now the 12 December and I keep getting assurances that the matter will be sorted today and that I will receive a credit and STILL my customers are waiting with no resolution in sight. The 2 customers blame me and are irate with me, yet every time I relay the assurances I am given, I am let down. If I could give no star, I would.