How long do refunds take?

I bought data bundles in December 2017 using your USSD code method. Your systems were offline at the time and I inadvertently bought 2 x 1GB data bundles as opposed to just the 1 x 1GB data bundle which I actually wanted. I immediately called your call center to rectify the mistake. According to the first person of contact, the issue was rectified immediately. I was issued with a reference number for this. At the end of January, I was actually charged for the additional 1GB data bundle even though it was supposedly canceled. Many phone calls to your call center later, and the issue is yet to be resolved. Before calling your call center today again, I spoke with another call center agent, who was going to call me back two weeks ago to confirm that my request was dealt with - No phone call from your agent up until today. Today, I called yet again, and spoke with another agent. I, again had to inform the new agent of my issue who has now issued me with yet another reference number saying that she will escalate the issue to the relevant department and that it should be sorted within the next 48 hours. It has now been almost 2 months since my initial call to your call centers and my issue is still, it seems, nowhere close to being remedied. Please follow up on these reference numbers: A2-6M2V-EY71AB A2-AQU9-YFHYM