Lack of customer service

Baby Boom Aeroport has always been my shop of choice when it comes to baby stuff. I have been shopping there for the last 4 years and have always experienced great friendly service until now. I bought a breast pump that didn't work. Due to their no return on breast pump policy I contacted the supplier directly. They said that I need to take it back to the place where I bought it, the staff their must then test it and they will take it from there. I dropped the pump off on Sunday and was told it would be sorted out on Monday. Monday came and went and I heard nothing. Most of Tuesday went by with no word from them so I decided to phone and follow up. The phone was answered by a rude man who told me that they are having problems with their phone lines and someone will get back to me. I don't understand what their phone lines have to do with sorting out my pump. And still no one has gotten back to me. As a breast feeding mom I need a breast pump and they are taking their time and being very unhelpful. I am very reluctant to ever shop there again due to this terrible service when I needed them the most.