Makro online's service

On 15 December 2019 I purchased a few items online at Makro. The parcel was partially delivered on 10 January 2020, with one item automatically cancelled. I got the cancellation notice via email, with no reason why it was cancelled. I checked online, and the item was available to order, so it was in stock - but not at the same price as I paid for few weeks ago.

I sent an email to Makro to enquire why I can't get the same item at the promotion price which I already paid for, and haven't received an item to date.

Now I have to phone and email wrt the refund due to me, and was informed that I need to send them my bank statement as it should've reflected in my account already. According to Makro customer service, the item was refunded on 7 January 2020, and should take 7-10 days from that date. Although I confirmed that there's no refund entries on my account, they insist I should send my personal bank statements to an unknown mailbox.

I just want some service, since to date its been a terrible experience.

thank you