Clicks online

Good day, I've made a online purchase almost Three weeks ago, I have fetched my parcel 9 days ago and on my way Home I noticed that one of the product's ml was not correct, instead of a 500ml which was advertised online which I purchased I was given a 50ml, the next day I went instore and spoke to the manager/supervisor and a lady for which was allocated the department and was told the product does not have a 500ml and there is nothing they can do and I should call the online department and get assistance, they was very rude and did not understand the fact that I purchased what was advertised and I have made two trips to the store and they hadn't solved anything, customer service was extremely awful from the Ballito junction store. I need assistance with my purchase and Info to what steps you can help me with excluding a refund.