Bad service and people skills

I received extremely poor customer service at the Pretoria Central store. I returned a router because I was going to be in the rural areas for the next three months and would not be using the service. The consultant who assisted me, Sylvia Machacha, was handling multiple tasks at once. She inspected the router, repackaged it, printed documents for me to sign, and I completed everything as requested. She then told me to leave my contact details and assured me that she would send me a reference number for the cancellation. It is now Tuesday of the following week, and I have still not received any communication. I tried calling the store, but the phones are not working. I then contacted 135, where the agent informed me that no cancellation was processed on the system and that I must return to the store to resolve the matter. This is completely unreasonable, as I am already in the Eastern Cape. I should not be inconvenienced and financially burdened because an employee failed to perform their duties correctly.