This is a non-delivery scam. Read How to Avoid A Non-Delivery Scam
As an example of what you could be dealing with, here are some Cameroon scammers that have been identified as living in Ukraine:
Stephan Nsansi
Henry ABUNAW a.k.a. Bubu Dre
Peter Fombang
Paul Ojong Ndip
Ayafor Trésor Zerewoh
Ify Peters
Valery
Peter Bide Nzegge
Charles Nganje
Innocent Peters, a.k.a. Ify
List of identified Cameroon Scammers
Samrex Global Trading Ltd
Katerynyns'ka St, 34 Odesa, Odes'ka oblast, Ukraine
Odessa - Ukraine
Sales Manager: Oleksiy Yoraslav
Tel: +380 (98) 134 91 24
WhatsApp#: +380 (98) 134 91 24
Website: http://samrexgloballtd.com/
Email: info.samrexgloballtd@gmail.com
Email: info@samrexgloballtd.com
5.45.66.235
Domain Name: SAMREXGLOBALLTD.COM
Registry Domain ID: 2360939912_DOMAIN_COM-VRSN
Registrar WHOIS Server: whois.namecheap.com
Registrar URL: http://www.namecheap.com
Updated Date: 2019-02-15T09:59:00Z
Creation Date: 2019-02-15T09:22:17Z
Registry Expiry Date: 2020-02-15T09:22:17Z
Registrar: NameCheap, Inc.
Registrar IANA ID: 1068
Registrar Abuse Contact Email: abuse@namecheap.com
Registrar Abuse Contact Phone: +1.6613102107
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Name Server: NS1.NEXTGENHOST.NET
Name Server: NS2.NEXTGENHOST.NET
Name Server: NS3.NEXTGENHOST.NET