Wumdrop service not satifisatory - delivers are not made

On 19th May 2020, Makro informed me that they handed my parcel to Wumdrop for delivery. On 20th May 2020, I enquired from Wumdrop via the order tracking facility and was informed that my parcel would be delivered before 17h00 on the 20th (email received from them) When I did not receive the parcel I rep**** to the email that the parcel was not received. I had no response to this email to date. On 21th May 2020, I again enquired via the order tracking facility about my parcel and had NO response. Today, 21 May 2020, I went again on the Wumdrop order tracking site, to find out where my parcel is and noted that they just cancelled the delivery and returned the goods to Makro. This is extremely unprofessional as they cited bad address as the reason for the non-delivery. I have had Makro deliver three different delivers to the same address during the lockdown period and I received all three packages. So why would the address now be bad?