Concern Regarding Online Tile Order and Collection Process

I recently ordered a box of tiles online to replace broken ones in my lounge. During the checkout process, I was given the option to select a branch for collection, and I chose CTM Southgate. I made payment immediately after completing the order. Shortly thereafter, I received a call from Princess at the online center to arrange collection. I was then informed that I could not collect from the Southgate branch because they had no stock. I explained that the website allowed me to select Southgate for collection and did not block the order or indicate any stock issues. Based on this, I assumed my order was confirmed and ready for collection at my chosen branch. When I requested to speak to a manager, I was unsuccessful. Instead, I was repeatedly told I only had two options:

Wait until next year when stock becomes available at Southgate, or Collect from another branch, which would require me to travel to a different area—an inconvenience, as I specifically chose a branch close to my residence.

This experience has been extremely frustrating. The online purchasing process failed at multiple levels, and the promise of convenience offered by the website was not delivered. Now, I face additional costs and risks: my installer is scheduled to fix the tiles, and I may need to travel far to collect them. The email I received after placing the order also does not align with the service I received. Overall, the experience with the online consultant was disappointing and did not reflect an understanding of what an online customer experience should be.