one till open in entire store!!!!

Firstly I al into the store, security in front put tag on my exchange. I ask her where are exchanges.. She says 'inside'.. I say where inside.. She says to the left. I walk to the left and all around the store to find myself at the right of her by customer services where stands a sign 'closed-- proceed to men's tills'. When I get there there is such a queue with many customers complaining how tie can be the only tills open in the entire store???? One till in the whole store!!!! This is the 2nd time I have been here and the same thing has happened!!! I have been waiting at the ONE till for 15 minutes for a lady jus to come give authorization!! Absolutely terrible!!!!