I placed an online order on Sunday with a nursery renowned by RHS for its lovely perennial plants. P&P was £9.50 extra and their website indicated a 3 week wait for delivery. I was fine with this. The website indicated that they would combine orders provided that the initial order had not been dispatched.
The following morning I decided that I wanted to order another plant from them and emailed them asking them to add it to my existing order. I put the order number into the subject heading, ie 'Order No: Txxxx', as per their original confirmation.
At 8:30am this morning I received an email from them stating that they would be dispatching my order today unless they heard back from me that I would not be around to take delivery. I emailed them straight back and reminded them of my extra plant that I had ordered.
At 3pm I got an email from them saying that they had discovered both my amended order and my reply to their email today in their junk folder and that they were 'terribly sorry' but it was too late for them to do anything about it.
Would it be unreasonable for me to expect them now to send me the extra plant I ordered without having to pay £9.50 postage again? (Obviously I'd pay for the plant, which was an extra £10.) I think that to quote their order number in the subject heading of my email only to have it go straight into their spam folder is not my fault, but rather their responsibility for setting their spam filter incorrectly.
Or should I just suck it up? I wouldn't be interested in a voucher unless it covered the extra delivery cost as frankly £9.50 for P&P is rather higher than other nurseries, and my original order was a treat to myself. Opinions from gardeners with experience in this area would be appreciated!