Terrible customer service and non delivery of items

I ordered face masks and one of the packs only had two masks instead of three. When I advised customers service, they gave me a 15% off my next purchase voucher. So they are basically saying that I need to spend more money with them to correct their mistake. I tried to explain this to them and Lee-Ann from their customer service did not understand why I was not happy. Why with I need to spend money to fix an error that was not mine. Terrible customer service. ORDER #***