MDS Collivery poor delivery service

Collivery MDS sent an email to me on 09 April notifying me that they will deliver my parcel before 16h00 on 09 April. On 09 April at 17h11 Collivery MDS sent another email to notify me that they will not deliver on 09 April, but before 16h00 22 April. Collivery MDS did not deliver within 3-5 working days according to their policy and they could not deliver despite the fact that the parcel was on its way to be delivered. Collivery CEO wrote in his reply to me that he is irritated writing to me after I laid a complaint.