Complaint to Sainsburys

Just made a complaint to Sainsburys.  I put the following:

I had a grocery order to be delivered today.  Originally it was over £40 and had a delivery charge of £1.  I deliberately chose a saver slot to minimise this delivery charge.

I did make an alteration to my order yesterday.  It shouldn't have taken me below £40.  But, I now realise that the 10 bags of jelly beans (50p each) I had originally ordered must have been taken off my order when reordering.  I never realised this as the reduction in cost was more or less disguised by a £6 increase in delivery charges.

Hence, when I received my receipt today it was claimed that everything was there that I ordered and that my delivery charge was £7 (not £1 as I expected).

I was confused by this until I noticed the jelly beans weren't there on the receipt.  And when searching the site, they are no longer available.

Why was it not brought to my attention:

a) That the jelly beans had been taken off my order?
b) That due to this, my delivery charge had increased from £1 to £7??

Now I've had to cancel my order, and reorder the very same groceries for tomorrow.  Meanwhile, I have virtually no food left in my house.  I am very dissatisfied and will be writing up about this.

I think it's a bit rich for them to cancel the jelly beans then increase my delivery charges by £6 into the bargain and not inform me of any of this!   I actually rang up and cancelled the order as they refused to rescind the £6 extra delivery charges.  I never complained at that point as I thought I must have made a mistake.  It was only after the phone call that I noticed the jelly beans are not on the receipt.  I feel irritated, and I have virtually no food left!