Useless Service!!

I do not understand how on earth it is impossible to amend/adjust an order I already placed. I called in and ordered the On the Double for R129, than I called back about 10 mins later to adjust my order to the On the Double feast for R209. Firstly the call centre couldnt help me and put me through to the store, the guy who answered the phone advised that my request will not be possible and this after putting me on hold without notifying me. I than asked to speak to the manager Felicia who told me that she cannot help me because I placed my order online...I rectified her saying that I called in to order than she continued to say "well ma' am..we cannot change the order because we have it in the system, u can only change it if it is not in the system yet" I have never....... But ah well, I guess this is the type of service Debonairs Kempton Park(Monument road) has to offer to loyal customers. Thanks, but no thanks!