Poor Service

On the 8th January 2018 I placed an order for a dog collar online. I immediately paid. They state approx. 15 days delivery. I tried contacting them on 3 occasions. On the 29th January 2018 I received a mail from them that the parcel will ship the next day. Today is the 12th February 2018. Still no parcel. I have mailed them 3 times with no reply. Should I not receive any answer from them by Wednesday 14th February 2018, I will be laying a charge of theft against them.