Guaranteed same day delivery

I placed an order online on the 12/06/2015 at 10:37 and chose the guaranteed same day delivery option, which includes an extra delivery fee. I followed up with the call center at around 16:00 as the tracking page showed no update yet. They said they will look into it and get back to me which they never did. I never received my order, and sent them a mail the next morning. They apologized and said I will get a refund on the extra fee paid. I received an sms later that day stating the parcel is with the courier and I will receive a call for final delivery arrangement. Three days later, I rep**** to that email asking when I will receive my order, and they said they will escalate the issue to the courier responsible. I received a call from Mr Delivery the next day, they said they will find out whats happening with the parcel. Haven't heard anything again.! Today is the sixth day since my order, nothing. Even the track parcel page shows no actions whatsoever. I'm really disappointed and just thinking of cancelling the entire order, full refund and take my business somewhere else!!! Please escalate this issue!