PUDO - Disgusting

I am disgusted with PUDO. Yes I made a mistake and my intention to still use the booking I have ordered. I swopped around the drop off and pick up address and I discover it when I wanted to put in my parcel in the locker. I contacted them immediately to tell them about my mistake and asked them to swop around the addresses , which I was informed that they can not do this. You tell me they can not change this........................and I just have to make another booking. Now they refuse to refund me. In there terms and conditions it say that if you do not use the booking you will still pay. I agree with this but not if you made a mistake,contact them and ask to help . In my eyes this is *****ing. Every computer system you can overwrite entries.