a piece of Japanese curry paste

I bought a piece of Japanese curry paste when I went to the centre of London. I didn’t realize that they charged more than I had the pay on my curry paste because I bought other ingredients and paid altogether. When I paid I thought it was a bit expensive and strange but the shop was crowded and I need to move out soon after I got my change. A piece of Japanese curry cost ￡1.5 but they charged me 4.5. They charged me three times as much as the usual price. I called them but the reaction of them was really bad.
The person who picked up the phone said that the many I dealing with was quite small. Moreover he said that the place I lived in is not so far from the centre of London so I should come as soon as possible.
I felt against him and said that if he thought it is not far he should bring the money to my place. He could not say no logically because he himself said that it was not so far to me.
He said he would bring but need time to arrange many things.
I know he may not be a bad person but bit too honest. Even if he thought the money I was dealing with was not so big and the place I lived was not so far, he should not have said that to me. I can not believe he comes.