Shocking Customer Service

Bought a powerbank in early January 2023. It arrived on time. However, the powerbank is faulty - it won’t charge any of my devices! Have followed all the proper channels to request a refund, but to no avail. There is no person to person contact. When I send an email I get told to use the WhatsApp number. I have left 14 messages on WhatsApp and they have read it, but they don’t respond. Onedealaday has no customer service, once they sell you the product, they are finished with you. It’s almost like they cut you off. They should not be allowed to sell goods online with such a pathetic attitude towards their customers.