Unsatisfied with service

Firstly I received a discount voucher via email from them, which did not work, after speaking to numerous call centre staff, I was finally assisted and a new voucher was issued. So I proceeded to place my order for Valentine's day. I selected my date of delivery (14-02-2016) and only a selected few items were available for delivery on V day as it falls on a Sunday. I made my selection from the options available, placed and paid for my order, only to be called 5 days later (today) 10.02.2016 to inform me that they can not deliver the item to me as they do not deliver on Sundays. They will only be able to deliver on Monday as they use a courier service. I have another order that is placed by them that will be delivered on 14.02.2016, so i asked why they can not deliver the 2 orders together. which the lady rep****, they can not as that 2nd item is from another department and the courier company they use does not make deliveries on Sundays. Now if this was the case from the beginning why offer selected items for delivery on V-day. I feel that they should make a plan to ensure that my order get delivered. I paid 2 delivery fees as well. If you offer a service then deliver that service