Horrible sixty60 service from call center agent

I Had the worst experience with a call centre agent on checkers sixty60. I Placed an order and one pf the items was wimpy 1kg chips. I had not selected and alternative and when my order was delivered it had been substituted with McCain 500g chips for T17 more! I then call the call centre and was connected to the worst agent ever who accused of of accepting the substitution on the app even though I advised him I had done no such thing. He claimed he could see it on the system where I accepted the subtitution which was a blantant lie. We argue over it and he tells me I will not be refunded because I clicked on a push notification abd accepted the substitution which as I stated did not happen. I get angry, ask to speak to someone else, he refuses and I hung up. I called back and got a lady called Lamiez who explained that because I didn't select an alternative, the system did it fir me but she confirms that there was no record of me accepting the substitution on the system like the previous guy claimed. I did ask for his name but he didn't give it. I am disgusted at the way he **** to me claiming I accepted the substitution which was a lie! I am beyond mad