Perfect Dealz bad service

I order something on perfect dealz and i wait long time for the delivery, when i received the item i ordered it was the wrong item, i tried to call them on all their numbers and there was no answer every day, finally after a few mails and 2 weeks after somebody respond back to me with a mail that they noticed that they sent me the wrong item and i sent them the picture off what i order and what i have received, they apologized for the wrong item they said they're sorry for the inconvenience they caused and will replace the item the following week that was now 2 weeks ago and not yet heard anything from them and they also dont respond on my mails. Please can you help? Don't know what to do now because they dont respond, what is the next step forward.