items late when postage paid

[elegantfool2016]

I paid 1st class postage totalling £6.80 for 2 items from the same buyer on the 8th April. The delivery date was 12th -13th April.
On the 16th April I contacted the buyer as I had yet to recieve the items plus I was frustrayed as it was now easter bank holiday so i would have to wait even longer. (fri 14th and Mon 17th)
The buyer claimed to have posted them the day before I contacted them (15th) and that they were late due to ebay not taking the bank holidays into account when calculating delivery dates. They went on to say that as a result I would likely recieve them on wed 19th or thurs 20th April!!
My issues are
a.These items were posted 2 days AFTER the expected delivery date.
b. becuse they were posted late the items got caught in bank hol post causing even further dalays
c. Even if posted on the 15th, and even if the 17th is a bank holiday, if posted 1st class why would it arrive on the 20th
d. both items are small and not heavy and I wasnt offered combined postage and paid £6.80 for 1st class post only to still be waiting 10days after purchase!!(I did not ask as I didnt notice they were from the dame buyer till later but if they arrive in one package It would be a liberty considering the above issues)

I have asked the buyer to refund my postage fees and stated the above. They ignored me. Do I have the right to ask for this or anything at all. Could I ask for a full refund and refuse the items all together. If not, what should I do? ps. there are 2 other items where the same issue applies and I have paid quite a lot in postage fees( all on the 8th april) only to still be waiting for items on the 18th (today).
Please tell me there is something other than feedback that I can do. thanks.