Very unhappy

I am not a very happy customer with Multichoice. I was sent an sms on the 26th November 2018 advising me of a special for R749 per month with a free DSTV Explora. I responded the next day and followed up with a phone call every week. I finally got a call from a call agent on the 21st December 2018 telling that you are out of stock with that special. I explained that I responded to the sms and called every other day and was told to wait for a call centre agent to call me. The call centre agent explained to me that I can only get a price lock for R900 some odd. I feel that if I had been called back after numerous attempt to chase multichoice I would have qualified for the special. Because they called me back late I lost out. I don't think that treating a customer who has been a loyal client for nearly 15 years is right.