Poor service on delivery of new handsets

On Saturday 4th July I did an upgrade for two phones on my contract with MTN at the MTN store in the Brits Mall. The upgrade was for two (2) Samsung S20 plus handsets. Unfortunately the handsets were not in stock but the lady that I dealt with told me after checking that "there were plenty at their warehouse" I agreed to wait for them to be delivered to the store for me to collect. Since then I have had several SMS messages confirming my order plus the 2 order numbers (*** & ***) and a confirmation SMS on the 10th July from Maverick MTN to say my phones are on route to the Brits MTN store. This morning the Brits store tell me they have not received the handsets and that they don't know when they will arrive as there is a huge backlog on the supply of the handsets. I have now been waiting for over 11 days(4 days since the message that they had been dispatched) and there is still no sign of the new handsets or even a fixed date for the delivery. I have had issues with poor customer service from MTN in the past and I am now considering moving to a different provider if I don't get my handsets very soon. I will appreciate it if someone can please tell me when the delivery can be expected and give me assurance that MTN do care for their customers