Terrible telephonic Vodacom service/deals

My mother has been paying for a wifi router for the past year. Vodacom telephonically offered her a 5gb day+night wifi router and only sent her a sim, promising she could put it in her existing router and it would work. After numerous phone calls to Vodacom customer service, they told her everytime that it should work. Well, This is the second time she is paying for a service that she is not receiving from Vodacom. If you make the right deal with Vodacom, IN PERSON IN STORE, you will be happy with their service. But DO NOT MAKE DEALS OVER THE PHONE, no matter how tempting the offer. She is not that educated in terms of the latest technology, and she just accepted another offer over the phone, being promised a laptop. The laptop now only has 70gb memory. Luckily I was here to inform her to do the right thing. Please, if you are not that up to date with technology, do not believe a word before speaking to trusted friends who do know a lot about it.