Refusing to refund my money

I went through the app to send a parcel locker to door. I looked at the measurements and my parcel was within that. I drove to the drop off location to place my parcel in a locker only to see that the locker was way too small (Much smaller than given measurements). I immediately submitted a support ticket on the app as I could not leave my parcel in the small compartment but I already paid.

They communicated back and forth with me and at the end stated that I could not get my money back because I reserved space for potential other clients. Take note that courier came to collect my "parcel" just part 9 the next morning which made it available to use again. They told me that I could have changed to a bigger box but how was I suppose to know. They just said it is mentioned in the FAQ's. That's not the first this I'm going to look at, I firstly contacted the support team. So now they took my money and I'm still sitting with the parcel which I refuse to send through Pudo since I won't be spending anymore money on them!