Disappointed client

I am not happy at all, at 16h20 I called steers and I was told y order will be ready in 15 min time.. I went there 20 minutes later trying to give them enough time to prepare my order. When I arrived I was informed that the order will only be ready in 20 minutes time. This is unacceptable! Why will I be told that my order will be ready in 15 mins and then when I arrive after that 15 mins, the mins are now extended? Do you consider people's time or commitments? Stop stating the time our meals will be ready, knowing that you guys don't know how to manage time!!!!