Distance Seller Cancelled and Refunded all but one item, but not the Postage fee

Amadeus_Onyx

Every year my wife wants a few specific types of petunia to plant, and we sometimes struggle to find it locally.

This year I orderd a large amount from jparkers on 19th April.
Their T's&C's include a number of of conditions but I think the relevant ones are (in summary):
1. The charge a single delivery fee per order, but items may be dispatched separately
2. Items are delivered when ready, and differnt items have different lead times
3. They have a 7 day return policy 

As they charge a single fee I added a small item I wanted as well. All the items on our order had the same lead time: 

3/4 Jumbo Plug Plants

M, V

Late-May, whilst stocks last

Delivery within 21 days

Pots.Modules

KP, SP,EP

Mid-May, whilst stocks last

Delivery within 21 days

The one item that I ordered arrived Promptly, well before the 21 days. The others unfortunatrely did not.

After weeks of chasing J Parkers cancelled the remaining items early June. I received refunds for those items. My problem is I've now paid £5 delivery for an item that cost £3.  I would not have ordered this item if not for buying the other items. 

The response from them is:
"The reason why the postage has not been refunded is because you have had the Cornus which was part of this order so the delivery covers that item."

I'm well outside the 7 days to return them for a refund also. What are my rights in this case? 

Aylesbury_Duck

What would the delivery fee have been if you'd ordered that one item only?

the_lunatic_is_in_my_head

From my understanding, you are entitled to keep what was sent if you wanted to keep the one plant and pay the delivery fee or are entitled to reject what was sent for a full refund, return costs would be on them. 

This is covered under Delivery of wrong quantity

https://www.legislation.gov.uk/ukpga/2015/15/section/25

(1)Where the trader delivers to the consumer a quantity of goods less than the trader contracted to supply, the consumer may reject them, but if the consumer accepts them the consumer must pay for them at the contract rate.

If you inform them you are exercising your right to reject as per Section 25 of the Consumer Rights Act 2015 they may just refund the £5 to be done with it (that would certainly be the sensible thing for them to do anyway). 

I'm also not sure that live plants are liable to deteriorate or expire rapidly but I'm sure most plant sellers would like to think they are so there may be a right to cancel but nothing certain on that.