Customer service at call center

I had difficulty to access the Internet. I called Starhub. The hotline staff transferred me to a technical expert. I was left holding on to the line for 5 minutes waiting for the technical expert to receive the call. As I was using my mobile phone, it was quite costly to be holding on.  I gave up.

The call center staff should ask for my mobile phone and get the technical expert to call me. This is only fair to the customer. But most call centers have a policy not to call the customer. This policy should be changed.