Unfair offerings

So I've been a Telkom mobile client for about 4 years now and as my mobile internet contract is up for renewal I wanted to change to their April special of 10gb + 5gb with a router for R199 per month. I filled in my application and it was sent for approval, however a few days later I was phoned by someone from Telkom who informed me that this special is only available to new customers and since I was already a customer I did not qualify for the offer?? How and why would you discriminate against your loyal and existing customers by not allowing them to make use of the same deals as you are offering new customers? Because to me that just means you are going to loose your existing customers. I also requested that they cancel my current contract and I then sign a new deal and was also turned down. This is unfair and also a flawed business model that will make you loose customers, very disappointed and won't be using telkom again.