Not selling when the customer wants to buy

I decided to do some shopping in the last few days and I was surprised to find how much the sales people in different shops across Cardiff really didn't want to sell to me.

While looking for trekking shoes I spent 5 minutes waiting for someone to ask for some shoes that I liked on my size, when nobody came I went all the way to the till and asked there. I’m sure all of this is reflecting a high level of interest in buying trekking shoes, so I was a bit frustrated when they came back to tell me they didn't have the shoes on my size and the when away to the till. Their opportunity to make a more valuable interaction with me was lost, it would have been easy for them to tell me something more engaging, for example: sorry Sir we don’t have those shoes on your size now, they will arrive on Monday; or can I suggest these shoes? They have similar features and price to the ones you were looking for. Any of these answers would have made me come back or buy something else from them, now I will never go back.

A couple of days after that I was thinking about changing my mobile phone and a similar thing happened to me, basically if I wanted to change my phone I needed to upgrade my plan through a phone call first, very big turn-off.

Is it really too hard to provide good service to your clients? Are you really trying to sell what your customers want to buy?