Incomplete order refusing respond

I ordered two fatherday special from canvas centre and I must say the initial interaction was quite pleasant. I ordered two canvases and part of the special is you could custom a coffee mug for your dad. The order arrived and I had one missing cup. I informed them immediately and they responded by asking which cup was missing.. After sending the information I have had no communication form them even though I tried to contact the several times. needles to say these where fatherday gifts and my Dad got have a gift.