Extremely poor customer service form Woolworths Online

On Monday 18 December I ordered/bought an item at Woolworths Online as the correct size was not available at my local outlet. The item was delivered on Tue. 19 December, but although I ordered a LARGE, a MEDIUM was delivered. I immediately called the call centre to report the mistake. Although the agent indicated that she would inform the warehouse and arrange for a collection of the wrong item and a delivery of the correct size, nothing happened. I made contact on several occasions, either via the call centre / customer services or email, but up until today, 8 January, the matter has not been resolved. On Friday, 5 January, I called Woolworths Head Office and requested to speak to a manager who can assist me in this regard - without being informed I was once again transferred to Woolworths Online - the agent promised to call me back within an hour and arrange for collection of the item either that same day or today, Monday, 8 Jan. When, after 3 hours the return call was made, I was not able to answer my phone. I responded on the email sent thereafter to request collection today before 12:00. Their courier company(RAM) informed me of a delivery to take place today before 17:00. they have 5 minutes left to do that as it is already 16:55. Efforts/Requests to speak to a manager of customer services or Woolworths online, does not bear fruit. I contacted Woolworths via Twitter(X) and Facebook and replies indicated that the matter will be escalated also came to nothing. I am at my wits end as it would seem all my efforts to have the matter resolved are unsuccessful.