Double check your order on specials when you purchase from this company

In February, Cosmetology offered a promotion featuring a "4 for the price of 3" special. Given the high cost of Mother Kind products, my friend and I decided to take advantage of this offer. Instead of the original price of R940, we paid R705 for four items I placed my order for the three products and made the payment, under the assumption that the fourth item would be automatically added to my purchase. In my haste, I mistakenly completed the order under the wrong profile, resulting in our front office receiving the initial confirmation email. I promptly contacted customer service to rectify the error, and the representative who handled my inquiry corrected my email address, who probably saw that I purchased 3 items, who never bothered to query that with me. However, when the products arrived, only three items were included. I sent an email regarding the issue, and a salesperson subsequently called to assure me that she would investigate the matter. The following day, I received an email indicating that, unfortunately, they could not assist me. This experience has left me with a lingering distrust of online purchases. Having made the purchase during a special promotion, I feel that I have been unfairly treated due to the error. It raises concerns about how many others might be in similar situations, feeling powerless against such companies.