H20 Water, BWT, poor customer service

I am very disappointed with H2O Head Office, not the branch I used. I purchased a filter for my counter before I got divorced. The incorrect filter was sold to me and Head Office BWT, refused for me to return the filter, even though you can see clearly that the filter was brand new and had never been used. Simply saying, that i need to purchase the right filter makes no sense to me. It is clearly marked H2O. Yes, I admit I don't have the receipt anymore with getting divorced and moving etc. I would have thought that keeping customers happy would be a positive impression for the brand. Due to this, i will not be using H2O products going forward.