Poor service at Vodacom, Forest Hill Mall

I am so frustrated with Vodacom. On the 21st March I did an Upgrade and took a V18MR19556 package which contained an ACER ASPIRE, keyboard, WIFI Vodafone R216 H plus a terabyte external hard drive. After signing a contract I was given everything in a package except the terabyte hard drive. The store manager asked me to collect it on Friday 23rd of March 2018. On that Friday I was returned to come back on Monday 26th March. I have been going to the shop for this external drive but sent back, yet Vodacom takes the whole monthly instalment every month. How can a big shop like Vodacom sell something of which they know very well it is not in stock? the treatment from that shop says they don't care. I have escalated the matter with Vodacom customer care and Vodacom complaints and they keep on telling me that the complain is still open. I have been waiting more than two months for that terabyte hard drive. Now they want to turn the story saying the hard drive was a gift. I want it whether it was a gift or not cause I sign for a complete package nothing less. I am very frustrated by the Vodacom service and their excuses. Can somebody help me please!?