I think loyalty should not come into it. Its business. If the new company provides a better / cheaper service they DESERVE your business. Thats what makes the capitalist system work !
However, I have lived in 2 other countries where the market was de-regulated and found no need to change providers. The incumbent company (Qtel in this case) will improve their act, - I have no doubt.
As to learning a new phone number, - who needs to? Does anyone use anything other than speed dialling / stored numbers ?