Disappointing customer service

I bought items online on the 1 May 2020. I received one order however when I queried the second order I was informed there was a technical difficulty and not all orders were pulled through. I kept following up on my order and almost instantly received status updates. I was then informed my order was shipped on 27 May 2020. I then queried that I never received the parcel. Guess followed up with the courier company as well. On the 4 June I was made aware by the courier company that they were trying to find the parcel. They visited the delivery address and apologized on the 6 June 2020. However, on the 8 June 2020 the courier company calls me to ask for pictures of the item as they are trying to replace them. During this period guess online has not yet called to apologise and doesn't respond to my refund request. They have now stepped aside and made it my problem with the courier yet I purchased it from guess and not the courier company. I clearly informed guess that I needed these items for my child's birthday on the 10th June 2020. Instead of refunding me, the courier company must now go looking for these items which may be sold out. Guess no longer answers their land-line. Really disappointing for such a reputable brand and would not recommend buying items online.