Inconsistency of colour tone

I have been using the MAC foundation for a few years now and was very happy with the product until recently. The inconsistency of the colour tone of a designated shade eg. 5.0 from one batch to the next and different bottles within a batch of the same shade, is extremely disappointing. This, coupled with R525.00 later and staff at the Mall of the South MAC branch telling me that there is nothing they can do about it , albeit a manufacture's defect, leaves me scouting around for a new range to support.